The Ancient Walled Oases of Northern Arabia

Description

North-western Arabia lies between present-day south-eastern Jordan and the desert areas of southern Syria and western Iraq. It is delimited by the northern part of the Red Sea coastal strip, paralleled by the Hejazi mountains which border the north-western interior sandstone plateau of Hisma reaching up to the plateau of Harrah, by the Nefud desert, on its eastern fringes, and by the basin of Wadi Sirhan. Prior to its present arid climate, the region has experienced successive climatic variations with several wet periods providing a favourable environment to human communities especially in the Early to Mid-Holocene period. The so-called “green desert” of that time provided extensive grazing lands, lakes, and high aquifers to Prehistoric nomadic populations whose presence is attested by various remains ranging from Palaeolithic to Neolithic tools and bifaces, petroglyphs, as well as funerary and rituals stone structures.

By 4000 BCE, a Rapid Climate Change (RCC) phenomenon, resulting in a severe decrease of precipitation, obliged the north-western Arabian populations to partly abandon their mobile life modes and in fine to establish permanent settlements in areas with high water tables where they created an oasis system. These major Early Bronze Age changes include the development of hydraulic and agricultural technologies (wells, irrigation, plough, cultivation of previously wild trees such as olive and fig trees), the construction of monumental architectural elements, large-scale pottery production, and greater availability of metal tools. The archaeological sites included in the serial property are characterised by the construction of big-scale ramparts protecting whole oases, including not only the dwelling district and economic centre, but also the cultivation area, the wells, and the necropolises. This phenomenon is a specific feature of the settlement process in north-western Arabia during the Bronze Age transition which differs from the simultaneous urbanisation process in the Mediterranean world and Mesopotamia and constitutes one of the most achieved examples of the human adaptation to the climatic transition from tempered climate of Neolithic period with permanent surface water, to an arid and desert climate.

The domestication of the camel, between the 2^nd and the 1^st millennia BCE, triggered a new era for northwest Arabian oases. Their ideal location at the crossroads of Egypt, the Levant, and South Arabia made them the keystone of international trade along the frankincense road. They became the essential bridge not only for exchanges of goods but also of peoples, cultures, and technologies. Their growing prosperity in the 1^st millennium BCE led to a revival of the integrated fortification phenomenon as a protection against inter-regional and local tribal attacks, and as a display of power but also as a barrier securing the cultivation zones and wells against environmental threats such as flooding and blown sand. The strengthening of their intermediary role in international trade, embedded northwest oases within a common narrative which made them at the same time competitors ­— the decline of Dumat Al-Jandal after the sack of Assyria in the early 7^th century BCE, led to the growth of Tayma, for instance — and interdependent, as the prosperity of the whole northwest Arabian region depended on the availability of a rich network of caravan stations. This situation led to the development of a specific political organisation, an Arab confederation, uniting for the defence of the hegemony on caravan trade, but also to a sophisticated institutionalisation and organisation of this international activity reflected by the use of coins, the profusion of inscriptions and graffiti attesting widely shared literacy skills, and specific urban planning with dedicated space and wells for caravan halts sometimes outside the oases’ walls.

The elements composing the serial property of The Ancient Walled Oases of Northern Arabia tell the millennia-old history of sustainable human settlements in a desert environment, through adaptive solutions to environmental change; the organisation of international trade and exchange through a well-established caravan-station network; and resilience in the face of political and economic transformations in the immediate and wider region over the course of history.

The Ancient Walled Oases of Northern Arabia serial property has 4 distinct components: two walled oases established in the Bronze Age (Tayma and Qurayyah) and two walled oases probably dating to the later Iron Age (Dumat Al-Jandal and Al-Ha’it). Collectively, they represent the heritage of exceptionally long-standing sedentary settlements which are a testimony to the legacies of successive civilizations from the Bronze and Iron Ages through to the Classical and Islamic periods. Two of them, namely Qurayyah and Tayma, developed long before the domestication of camels; and three of them remained active centres through to the Islamic era (the exception being Qurayyah). They share a unique characteristic: the edification of monumental walls surrounding the entire oasis, which likely contributes to explain their longevity and their economic status as caravan stations.

Tayma

Tayma, located between the Hejaz Mountains and the western part of the Great Nefud desert, is one of the most important and most studied archaeological sites in northwest Arabia.

North of the oasis used to be found a 20 km² paleolake at the southern fringe of which lies a wide palm cultivation area. The ancient settlement known as “Qoraya”, covering some 80 hectares, is located southwest of the palm groves, while the more recent old town centre, probably erected in the Islamic Middle Ages, is situated between the northern edge of the ancient settlement and the south of the palm groves.

Tayma oasis is characterised by the impressive remains of an enclosing outer wall protecting the oasis, erected between the 4^th and the 3^rd millennia BCE. The fortification encloses an area of 1000 ha with a perimeter of 18.2 km. A 3.2 km-long retaining wall in the north of the settlement divided the palm oasis from the salt flat to protect agricultural areas from erosion and the infiltration of saline sediments. More recent interior enclosure walls, dating from the Iron Age and later, protect specific areas of the oasis, including wells and Qoraya. The impressive scale of the fortifications is the proof of a strong local power, capable to raise the resources needed for its construction and maintenance.

Although the development of Tayma is strongly linked to the development of the Frankincense Road in the 1^st millennium BCE, the oasis was settled at least since the Neolithic thanks to the favourable climate prevailing in the Early Holocene period and the vicinity of a freshwater lake.  Arrowheads and bifacial tools from the 7^th to the early 6^th millennia BCE, and rock carvings bear witness of this early human presence. Aggravated aridity conditions in the region at the beginning of the 6^th millennium BCE reshaped Tayma landscape and redefined its human occupation pattern with the progressive disappearance of the paleolake. The availability of ground water, however, allowed human groups to continue settling in the area, progressively developing an early form of oasis cultivation during the late Neolithic period (5^th - 4^th millennia BCE). Scientific research suggests that the occupation of Tayma was continuous from the 4^th millennium BCE onward.

Beside agricultural activities, Tayma’s Bronze Age economy relied on the production of pottery and already involved commercial contacts with Syria and the Levant, long before the domestication of the camel. The Bronze Age cairns, south of the oasis, constitute its most ancient necropolis, later supplanted by circular graves in Rujum Sa’sa dating from the 3^rd and 2^nd millennia BCE, and by rectangular collective burials, in the 9^th - 5^th centuries BCE.

The transportation revolution triggered by the domestication of the camel by the end of the 2^nd millennium BCE led to growing exchanges with Egypt and the Levant and an increase of Tayma regional stature. The elongated rectangular Temple building in the southwestern part of Qoraya framed by a massive wall, displays a unique northwest Arabian building tradition, different from the contemporary architecture of the neighbouring regions. The wealth of the oasis attracted the last king of Babylonia, Nabonidus, who settled for ten years in Tayma in the mid-6^th century BCE. His presence is evidenced by a stele with a Babylonian cuneiform inscription and by other fragmentary texts. Then, Tayma passed under the rule of the Achaemenids, followed by the hegemony of the Lihyanites, based in Al-Ula, from the 5^th to the 2^nd centuries BCE. The Qasr Al-Hamra, and the temple’s monumental statues, illustrate Lihyanite domination.

The Nabataean and Roman periods are represented by the extension of the residential district, with the apparition of more complex 2-storey architecture, the reconfiguration carried out in the temple — including the construction of a monumental access staircase and of large basins supplied by 15 m tunnel water channel —, and the construction of large public buildings such as Qasr Al-Radam (a rectangular facility with tower-like fortifications located within the north-western town wall and surrounding a well). The Roman and Late Roman periods in Tayma also witnessed the development of metallurgical activity where copper and tin were melted and alloyed to produce bronze. Part of the raw minerals required for this activity were imported, reflecting the favourable location of the city for importing, producing, and exporting goods.

More recent layers of civilisations also contribute to Tayma’s rich heritage, such as Islamic inscriptions. The abandonment of the ancient settlement did not lead to the desertion of the oasis. On the contrary, Tayma oasis continued thriving, but its centre moved closer to the fertile palm groves, were still stands Bir Hadaj, one of the biggest well of the Peninsula. The continuity of Tayma’s history is further reflected by more recent architectural vestiges, including the Rummam Palace, and the modern city extension located southwest of the archaeological site, outside the wall of the ancient oasis.

Qurayyah

The site of Qurayyah lies on the eastern foothills of the Hejaz mountains range, (70 km northwest of modern Tabuk) in northwest Saudi-Arabia, along the path of the ancient trade route that crossed the Arabian Peninsula from South to North connecting Yemen with the Levant. Human presence in this site dates from the pre-pottery Neolithic era. After Neolithic frequentations, a sedentary settlement was established in the Early Bronze Age (early 3^rd millennium BCE). The first occupants of Qurayyah progressively shaped the site developing an agricultural oasis, by harnessing the surface water resources thanks to an advanced irrigation system. They structured the natural landscape with monumental architecture raising a protection wall all around the oasis; they developed olive tree culture and copper production, and later created an almost industrial pottery manufacture in the Bronze Age.

The Early Bronze legacy allowed the oasis to develop and thrive from the 2^nd millennium BCE to the early Iron Age and Nabataean and Roman periods. Qurayyah reached its golden age as the supposed capital of the Midian tribe during the Late Bronze age (1700 to 1200 BCE) with a territory extending in the Tabuk region (Dedan, Timna in the Wadi ‘Araba, Tayma, and Al-Bid’ were the other urban centres in the land of Midian). Their economic power relied on trade relation with the Egyptians, the rich mineral resources of their territory, and their sophisticated geometrically designed pottery production. After the Midianites, the Dedanites, the Lihyanites, and the Nabataeans took over. Qurayyah displays a rich Nabataean and Roman heritage, bearing witness of the evolution of the oasis after the Midianite era. The site was abandoned in the Early Christian era.

The archaeological site extends over approximately 300 hectares and is enclosed by a monumental outer wall of some 7 km, dated to the Early Bronze Age, at the beginning of the permanent human presence in Qurayyah. Inner walls are also found around the residential area, which is entirely fortified. The diversity of materials and construction techniques suggests that the different wall segments were built, consolidated, or added at different times. The northern part of the settlement is occupied by large expanses of fields, while the southern part, subdivided into several districts, gathers the dwellings, the economic activities and the religious sites carrying the legacy of the successive civilisations that thrived in Qurayyah.

The early-3^rd millennium remains of a citadel (acropolis), covering an area of 35 ha, is found on the south-western edge of the oasis, on a rock plateau 50-60 m higher than the surrounding plain. Two impressive, three-meter-high stone walls with built-in round and rectangular towers, are still standing. They underline the power of the settlement, capitalizing on the perfect far-distance visibility of the plateau. A free-standing tower at the eastern end of the Plateau completes the landscape of the citadel. The plateau overlooks the industrial and the walled residential areas of the oasis, where vestiges of sumptuous dwellings are found. Qurayyah is famous for its painted ware pottery production from the Late Bronze Age, which shares similar features with Levantine pottery while displaying a unique and original repertoire. The ceramics kilns were in use between the late 17^th and 16^th centuries BCE.

The biggest share of Qurayyah walled oasis is occupied by agricultural fields stretching over all its northern half. The oasis displays a very impressive network of partitioning walls and canalizations. Cultivation of these fields probably started as early as the 3^rd millennium BCE. In addition to agriculture, the fields were also exploited for clay extraction. A Roman period site with a 9.5 ha water reservoir used in the Classical period, was found in the middle of the fields.

Dumat Al-Jandal

Dumat Al-Jandal — ancient Adummatu in Assyrian inscriptions and Dumah in Biblical texts — is an oasis located in the region of al-Jawf at the southern end of the Wadi Sihran, 400 km east of Petra. Its strategic location made it a key stop on the East-West ancient trade roads connecting Gaza and to the Arabian Gulf, and thence northwards to Babylon.

The region of Dumat Al-Jandal displays a rich prehistoric heritage reaching back to the Palaeolithic. Rock carvings dated from the Neolithic and an impressive 35 m-long platform constructed in the mid-6^th millennium BCE near a necropolis (interpreted as a space dedicated to rituals performed by prehistoric nomadic pastoralist populations of Northern Arabia) are evidence of an early phase of occupation in Dumat.

Although it is difficult to date the first sedentary populations in Dumat Al-Jandal, Assyrian sources from the early 1^st millennium BCE already attest the existence of Adummatu, described as the thriving citadel of the Qedarite tribe. Dumat was a target of the Assyrian kingdom, that attacked and plundered the oasis in the early-7^th century BCE. Despite this traumatic event, Dumat Al-Jandal survived and later entered the Nabataean sphere of influence in the 1^st century CE, before being annexed by the Romans in 106 CE. The Byzantine and Islamic heritage of the city shows the continuity of its occupation that extends until today.

The archaeological site of Dumat Al-Jandal consists of two major enclaves:

The North-Western Valley: here were found fireplaces dating from the Early Iron Age, as well as much later structures, including a 2.5 km long rampart with a height reaching up to 4.5 m, a 160 m-long retention wall built around the 3^rd and 2^nd centuries BCE, and a vast freestanding open-air Nabataean triclinium flanked by towers.

The Historic District of Dumat Al-Jandal: protected by an inner rampart dating from the Nabataean era, it forms an extraordinary complex presenting a rich layering of successive civilizations. Its main monumental feature is the stone built Marid Castle, which gave the name to the city ­(jandal means stones) developed in the Nabatean era possibly on earlier remains. This fortress, lying on a small hill overlooking the historic residential district of Al-Der’ next to the Omar Mosque, was successively rebuilt and developed many times until the Ottoman period. This 30,000 sq. m district typifies the layering of successive civilizations typical of Dumat Al-Jandal and displays a characteristic set of features including: stone arches, stone buildings, mudbrick houses and narrow alleys, and water canals. Al-Der’ consists of approximately 40 dwellings of different size dating from the Mid-Islamic era that were built over Nabataean and Roman vestiges. The Umar Mosque, with its famous ancient minaret, is traditionally attributed to the Caliph Umar. Though heavily restored, it is an important Islamic heritage landmark of the city. Next to the historic village, now entirely emptied and preserved as an archaeological site, lies the ancient oasis area preserving important vestiges of the ancient water management system. Fifteen ancient wells are found in the surroundings of the castle. Their depth ranges between 15 and 40 meters and their diameter from 3 to 6 m; some of them are endowed with staircases integrated into the masonry. Field research shows that a significant proportion of these wells still have water, and that some of them were connected to a large network of underground qanat-s which provided water to the dwellings and to the orchards. The well-qanat system in Dumat, a still partially unexplored field of research, could shed light on the evolution of traditional oases irrigation systems.

Al-Ha’it

Al-Ha’it, located in Khaybar region some 140 km from Madinah, is a large and complex archaeological site still mostly unresearched. The oasis is firstly mentioned in Babylonian sources from the mid-1^st millennium BCE, but its monumental stone walls, surrounding the entire oasis, are much older and likely date from the Early Iron Age (end of the 2^nd / beginning of the 1^st millennium BCE). Important prehistoric stone structures are found scattered on the harrat lava plateau outside the walled oasis, southwest and northeast of the archaeological area. They notably include a series of “key-hole” stone structures aligned along a central axis, a large rectangular “gate”, and a “kite”, monumental witnesses of the long-standing human presence in the area.

Al-Ha’it — known as Padakku in Babylonian sources and Fadak in Islamic sources before taking its modern name that means “the walls” — forms an extraordinary well-preserved ensemble with ancient walls, agricultural fields, ancient springs, water distribution canals and wells that await to be studied in more detail.

In the 1^st millennium BCE, this fertile oasis was conquered, at the same time of other northwest Arabian oases, like Tayma, Khibra and Al-Huwayyit, by Nabonidus, the last king of Babylon, who aimed to control the ancient trade and caravan routes. An eroded stone stele on site depicts the king and attests his conquest of the town in 553-543 BCE.

The ancient oasis settlement includes two distinct sites enclosed by walls: the first, located to the east of the Islamic period oasis, is still visually evident as a settlement with well-preserved and impressive stone walls. It surrounds an agricultural sector protected by higher hills on the North and the South; the second one, mostly redeveloped in Islamic period, encloses the large oasis with its wells, springs, towers from different epochs, and three settlements that show a complex superposition of historic phases possibly ranging from the 2^nd millennium to the Islamic Middle Age. This impressive and extended system of walls, which could reach back to the Iron Age, has a perimeter of 9 km and encloses a 300-ha surface. Several rocky outcrops seem to have served as a foundation for an architecture of monumental scale. Many ancient wells, some of them abandoned, are preserved in this part of the oasis and attest of its former wealth. Most of the oasis is currently abandoned and only few parcels are still irrigated and cultivated.

Little is known about the archaeological site of Ha’it, and its entirely fenced domain represents a promising research field for future surveys and studies. The continuity of the ancient settlement, before the creation of the modern city, is attested by Early Islamic heritage, including palaces and forts.

Justification of Outstanding Universal Value

The serial property The Ancient Walled Oases of Northern Arabia adopts a comprehensive approach to the presentation and preservation of millennia-old archaeological oases sites aiming to integrate the ensemble of the technological and human elements that materialize 1^st) the oasis development process, 2^nd) the regional trade platform status, 3^rd) the durability of human settlement through time attested by the remains of successive civilizations, within a single serial property.

The serial property captures the long-term strategies developed by the oasis settlements to survive and thrive throughout climatic stresses and evolving geopolitical stakes on the one hand; and underlines their role in the development of civilization through international exchanges of goods, cultures, and technologies on the other.

The Rapid Climate Change (RCC) experienced in North-West Arabia at the turn of mid-Holocene, resulted in changing water availability patterns due to a decrease of precipitations. This led the populations living in the region to develop innovative and sophisticated hydraulic systems to tap into the subterranean water and the occasional flooding of the wadis, to ensure their food security. The well technology, and the development of complex canal networks supplying the agricultural areas, are representative of these innovations that constitute an outstanding example of traditional human settlement interacting with the environment.

Beside the well and qanat technologies, the proposed series sheds light on the unique know-how of the ancient human societies that settled the area skilfully adapting to the environmental context mitigating natural hazards. In Qurayyah, the residential and funerary areas were located on high flood-free positions. The mud-brick-walled ‘Residential Area’ in the centre of the site overlooked the artisanal areas in the southwest and benefited from direct water accessibility without the risk of flooding. The agricultural fields occupied transitional areas just above run-off of smaller tributaries and wadis to be out of reach of erosive heavy rainfall floods while profiting from the fertile alluvial substrates distributed during non-erosive flooding events. In Tayma, the erection of a wall between the salt flat and the cultivation area protected the fertile soil from saline infiltration. In Dumat Al-Jandal a retention wall was built to protect the oasis from the wadi occasional flooding and, finally, both in Al-Ha’it, and Tayma, inner walls were erected within the cultivation area to protect the fields from flooding and blown sand.

The construction of massive defensive walls enclosing the whole oases — not just the settlements, but also cultivated areas, water points and vital hydraulic structures — is a key feature of the OUV of The Ancient Walled Oases of Northern Arabia series. These “walled oases” constitute a unique specific feature, absent in most ancient oases of the region. This extremely ambitious defensive scheme required considerable investment, from the construction to the maintenance stages, and aimed at ensuring the long-term survival of the oases — and in fine of the Near East trade routes network — against environmental and military threats.

The local population did not only develop an irrigation system, to guarantee their food security, but ensured their long-term functioning with the construction of imposing walls extending for tens of kilometres surrounding the entire oases. The innovative technical solution adopted for their construction contributed to the oases extraordinary longevity spanning a few millennia. The segment-wall technology permitted rapid and localised repairs in case of punctual decay; buttresses supported and consolidated the closure walls; and the addition of successive layers of wall reinforced them to resist flooding. 

The ancient walled oases are not only an outstanding example of human interaction with the environment but are also representative of the caravan-station culture. These ramparts, often flanked with towers, were a powerful visual landmark, visible from afar, for the travellers and caravans crossing the desert.

Walled oases were essential not only for the survival of the oases per se, but also for the successful development of inter-regional exchanges with ancient civilisations of Egypt, the Levant and Mesopotamia. The Ancient Walled Oases of Northern Arabia played a critical intermediary role favouring exchanges and mutually nurturing progresses among ancient civilisations. The property sheds light on the technologies, logistics, and organisational skills that ensured the development and functioning of the oases, that were capable to host and supply with water and food passing by caravans on their way to reach their next destinations.

The profusion of graffiti and inscriptions, in multiple alphabets and scripts (including Cuneiform, South Arabian, Thamudic, Nabataean etc.), reveals that literacy was relatively widely spread, as it represented a necessary tool for successful international commercial interactions. The exposure of northwest Arabian oases to the regional trade network made them a hub of technological and cultural innovation and the elements of the series show an important exchange of human values within the Middle Eastern region, reflected by the spread of common regional features, sometimes adapted to local context. These exchanges with the broader Mediterranean and Mesopotamian regions also allowed the northern Arabian oases to develop their own features and techniques, such as the carnelian beads handcraft, the Qurayyah painted ware pottery, specific architectural patterns, etc. The intermediary role of the oases and their contribution to innovation is testified by the presence of industrial workshops, notably in Tayma and Qurayyah

Finally, the proposed series also displays important exchanges of human values through a wide span of time. The 4 sites — all embedded within a common northwest Arabian narrative which reflects the oasis creation process and the birth of powerful trading oases within the Qedar Arab tribe confederation of the 1^st millennium BCE — offer interesting specificities justifying their articulation within a unique series. Tayma and Qurayyah, which are both dated to the 4^th – 3^rd millennia BCE, experienced different evolutionary paths. Tayma is still a lively territory: even though the ancient residential area was abandoned during the Islamic era, the city developed around the archaeological site and one of the iconic monuments of the site, the Bir Hadaj is still active and used. On the contrary, Qurayyah witnessed the succession of regional hegemonies through the Midianite rule, the Lihyanite, the Nabataean, and the Roman occupations, but was then entirely abandoned. Dumat Al-Jandal, that developed around the 1^st millennium BCE, joins an extremely well preserved Early Islamic urban planning heritage, with the underlying (and older) Nabataean and Roman foundations. Finally, the ancient Padakku (Al-Ha’it) offers a very well preserved and yet undiscovered heritage and represents a promising avenue for future research.

Criterion (ii): Since the sedentarisation of human groups in the northwest Arabian oases, as early as the 4^th – 3^rd millennia BCE — long before the domestication of the camel — the inhabitants of these oases took advantage of their location, at the crossroads of the most developed civilisations of the time, in Egypt, Southern Levant, and Mesopotamia. The exchange of manufactured goods, such as metallurgy production and painted ware ceramics, and of raw materials, such as copper, but also the import of Mediterranean trees like the olive tree, the exchange of technology, including hydraulic engineering and architecture, bear witness of lively and fruitful dynamics that characterised these sites and nurtured the progress and innovations of early civilizations. The domestication of the camel intensified these exchanges and the exchanges of know-hows, and led to the elaboration of specific features, such as the oasis protection walls typical of The Ancient Walled Oases of Northern Arabia property, and to the development of local forms of coinage and writing. The series is a testimony to the antiquity of organised trade in the region and of the connection between southern Arabian civilisations, the Fertile Crescent, and Mesopotamia.

Criterion (v): Water management is a key dimension of The Ancient Walled Oases of Northern Arabia series. The development of well technologies — illustrated notably by the many wells in Dumat Al-Jandal, the monumental Bir Hadaj and the fortified well of Qasr Al-Radam in Tayma —, and by the water distribution technology — impressively illustrated by the water channel network of Qurayyah’s fields and the subterranean qanat network in Dumat Al-Jandal — bear witness to the development of oases and cultivation techniques, and of the human adaptation to changing environment. 

The ancient walls surrounding these oases represent another critical element of their heritage and of their potential Outstanding Universal Value. They materialise the strategy developed by the local populations to ensure the sustainability of their settlements, not only against attacks and foreign raids, but also against a hostile environment. These walls do not merely surround a fort protecting the power core of the city, but also form an ambitious protective defence system against natural hazard which could threaten not only the ruling political elites but also the survival of the oases’ agricultural fields. Retention walls protecting ramparts from flooding; successive layers of outer and inner walls aiming at countering sand winds; and protection walls to prevent the infiltration of salt from the sabkha in the cultivation area, all illustrate the human ingenuity to sustainably overcome hostile environmental conditions.

The walls are also representative of the caravan-station culture; they attest the considerable power and wealth of the caravan oases and their rulers, and the security imperative resulting from this status. They were also critical landmarks visible from the far desert and subsequently of high importance for caravan-based societies.

Statements of authenticity and/or integrity

Authenticity

The four sites included in the serial property present an extraordinary degree of authenticity both at the level of the monumental elements and at the level of their larger landscape.

The four oases provide a complete representation of the phenomenon of walled oases. They present similarities justifying their inclusion in the series, and differences that add to the potential OUV of the ensemble, each site bringing additional values to the series. Three of the oases have been studied for decades by Saudi and international missions that have excavated some of their most relevant elements. The restoration of the vestiges has permitted to preserve them without altering their original features, fully preserving the authenticity of the archaeological remains. The oasis of Ha’it, on the other hand, is essentially untouched, frozen in the situation it presented in the Middle Ages. Its authenticity is therefore “absolute”.

In Tayma, the ancient settlement was abandoned at the beginning of the Islamic era, resulting in the transfer of the historical centre of the modern city toward the centre of the palm groves, where the Bir Hadaj is located. The multiple elements of the archaeological oasis are listed and protected by a system of fences, set up and maintained by the Saudi Antiquities, that has prevented urban developments and transformation in the archaeological sectors. Bir Hadaj, an extraordinary ancient well, is also fenced and was in use until very recently, offering an outstanding example of truthful continuity of an authentic traditional use.

The oasis of Qurayyah was abandoned after the Roman occupation. Its location in a remote and inaccessible area safeguarded the archaeological site from modern urban developments in its surroundings. Furthermore, the site is entirely fenced to ensure its protection.

In Dumat Al-Jandal, the archaeological zones are partially embedded in the modern city. The Western rampart, located north-west of the city, though, is essentially located outside the area of urban development and is protected by fences. The Marid Castle, and the historic district below it, have been restored and are now accessible to visitors.

The oasis of Ha’it, still mostly unresearched, offers a fully preserved authentic state and its main archaeological sites are fenced. The historic villages that developed on earlier foundations have not been affected by modern development.

Integrity

The vestiges of the monumental walls surrounding the four oases display an excellent level of integrity. In Tayma, the outer ramparts are nearly intact as reflected by their impressive 18,2 Km length which almost fully surrounds the oasis, including the successive settlements and the cultivation area. In Dumat Al-Jandal, the segment of the nearly 3-Km long wall which stands at the Western Sector gives a sound illustration of the gigantic scale of the initial perimeter of the ramparts, while bringing a precious testimony of the different construction phases and techniques (including the use of buttresses and water retention wall). The walls of Al-Ha’it also displays a satisfactory level of physical intactness, and the contributions of each period are clearly visible and participate to the wholeness of the testimony borne by the site. Finally, in Qurayyah the inner rampart which protected the residential settlement is intact and sheds light on the strategy of dual rampart edification, even though the outer oasis wall is only partially preserved.

In the oases proposed for this series, the layering of successive civilizations is critical for the understanding of their potential Outstanding Universal Value: the historic districts of Dumat Al-Jandal, Tayma and Al-Ha’it carry the legacy of the different periods, from the Antiquity until the Early Islamic era. Qurayyah also represent the diversity of its past occupants, until the Classical period as the site was abandoned after the Roman occupation. This rich history is materialized by the multiple attributes of the serial property, including buildings remains, water management systems, and necropolises from different periods. These attributes, and the landscapes within which each oasis is integrated, still maintain a high level of integrity.

All the elements of the series are fully protected by the Saudi legal system and do not suffer from urban encroachments and other adverse effects of development and neglect.

The four selected oases include all the elements necessary to express the potential Outstanding Universal Value of the serial property and provide a complete representation of the walled oasis concept that conveys the property’s significance.

Comparison with other similar properties

Several ancient oases of the Arabian Peninsula and beyond are already included in the World Heritage List and provide interesting elements of comparison. Among them are notably:

Hegra Archaeological Site (Al-Hijr / Madāin Sālih) (Saudi Arabia, 2008, criteria ii, iii): The archaeological site of Hegra is the largest conserved site of the civilization of the Nabataeans south of Petra in Jordan. It features well-preserved monumental tombs with decorated facades dating from the 1^st c. BCE to the 1st c. CE. The site also features some 50 inscriptions of the pre-Nabataean period and some rock art. Hegra bears a unique testimony to Nabataean civilization. With its 111 monumental tombs, 94 of which are decorated, and water wells, the site is an outstanding example of the Nabataeans’ architectural accomplishment and hydraulic expertise.

Petra (Jordan, 1985, criteria i, iii, iv): Petra was listed as an archaeological site. Inhabited since prehistoric times, this Nabataean caravan-city, situated between the Red Sea and the Dead Sea, was an important crossroads between Arabia, Egypt and Syria-Phoenicia. Petra is half-built, half-carved into the rock, and is surrounded by mountains riddled with passages and gorges. It is one of the world's most famous archaeological sites, where ancient Eastern traditions blend with Hellenistic architecture.

Incense Route - Desert Cities in the Negev (Israel, 2005, criteria iii, v): The four Nabatean towns of Haluza, Mamshit, Avdat and Shivta, along with associated fortresses and agricultural landscapes in the Negev Desert, are spread along routes linking them to the Mediterranean end of the incense and spice route. Together they reflect the hugely profitable trade in frankincense and myrrh from south Arabia to the Mediterranean, which flourished from the 3^rd c. BCE until the 2^nd century CE. With the vestiges of their sophisticated irrigation systems, urban constructions, forts and caravanserai, they bear witness to the way in which the harsh desert was settled for trade and agriculture.

Archaeological Sites of Bat, Al-Khutm and Al-Ayn (Oman, 1988, criteria iii, iv): The site was listed as a serial archaeological property. The protohistoric site of Bat lies near a palm grove in the interior of the Sultanate of Oman. Together with the neighbouring sites, it forms the most complete collection of settlements and necropolises from the 3^rd millennium BCE in the world. Together, monumental towers, rural settlements, irrigation systems for agriculture, and necropolises embedded in a fossilized Bronze Age landscape, form a unique example of cultural relics in an exceptional state of preservation.

Al-Ahsa Oasis, an Evolving Cultural Landscape (Saudi Arabia, 2018, criteria iii, iv, v): In the eastern Arabian Peninsula, Al-Ahsa oasis is a serial property comprising gardens, canals, springs, wells, and a drainage lake, as well as historical buildings, urban fabric, and archaeological sites. They represent traces of continued human settlement in the Gulf region from the Neolithic to the present, as can be seen from remaining historic fortresses, mosques, wells, canals, and other water management systems. With its 2.5 million date palms, it is the largest oasis in the world. Al-Ahsa is also a unique geo-cultural landscape and an exceptional example of human interaction with the environment.

Cultural Sites of Al Ain (Hafit, Hili, Bidaa Bint Saud and Oases Areas) (UAE, 2011, criteria iii, iv, v): The site comprises a serial property that testifies to sedentary human occupation of a desert region since the Neolithic period with vestiges of many prehistoric cultures. Remarkable vestiges in the property include circular stone tombs (ca 2500 BCE), wells and a wide range of adobe constructions: residential buildings, towers, palaces, and administrative buildings. Hili moreover features one of the oldest examples of the sophisticated aflaj irrigation system which dates to the Iron Age. The property provides important testimony to the transition of cultures in the region from hunting and gathering to sedentarisation.

The Proto-urban Site of Sarazm (Tadjikistan, 2010, criteria ii, iii): Sarazm, which means “where the land begins”, is an archaeological site bearing testimony to the development of human settlements in Central Asia, from the 4^th millennium BCE to the end of the 3^rd millennium BCE. The ruins demonstrate the early development of proto urbanisation in this region. This centre of settlement, one of the oldest in Central Asia, is situated between a mountainous region suitable for cattle rearing by nomadic pastoralists, and a large valley conducive to the development of agriculture and irrigation by the first settled populations in the region. Sarazm also demonstrates the existence of commercial and cultural exchanges and trade relations with peoples over an extensive geographical area, extending from the steppes of Central Asia and Turkmenistan to the Iranian plateau, the Indus valley, and as far as the Indian Ocean.

The comparison with pre-Islamic oases listed above underlines both the similarities — with a shared narrative of hydraulic engineering innovation, prosperity, and cultural exchanges through regional commerce — and the specificities of the proposed serial archaeological site. The Ancient Walled Oases of Northern Arabia, successfully account for an intermediary role in international exchanges which is far older than the transport revolution triggered by the domestication of the camel and the subsequent development of the Frankincense Road. Consequently, the present file carries the ambition to display the oasis development process, from the 4^th millennium BCE onwards, as an integral part of the history of North Arabia and the region.

While most of the World Heritage properties mentioned above shed light on Nabataean heritage, the present file proposes a more integrated approach based on the layering of successive civilizations. This illustrates the specificity of The Ancient Walled Oases of Northern Arabia that stand out for their exceptional longevity and that, contrary to all the examples mentioned above, are still active (Qurayyah stands as the exception of the proposed series, but it similarly displays an exceptionally long occupation between the 4^th millennium BCE and the Roman era).

The cultural landscapes of Al-Ahsa in Saudi Arabia and Al-‘Ain in the United Arab Emirates provide outstanding examples of the oasis development process since the end of the Neolithic and illustrate the development of irrigation technologies in a desert environment, deemed to an extraordinary sustainability and longevity. In this respect, the archaeological sites of The Ancient Walled Oases of Northern Arabia are embedded within the same narrative of the human adaptation to environment and the development of hydraulic engineering to ensure a long-standing food security. Yet, the serial property narrative adds another key dimension: the role of the 4 oases in regional trade with the Levant, Egypt and Mesopotamia, their specific identity as powerful caravan-oases shaped by the successive eras of the Midianites, the Qedarites, the Assyrian and Babylonian interferences, and the Lihyanites, Nabataean, and Roman dominations. These civilizational patterns, deeply rooted in the North-West of Arabia and representing outstanding contributors to the history of regional civilizations, are fully evidenced by The Ancient Walled Oases of Northern Arabia.

The comparison with other major ancient trading cities is highly relevant. The Proto-urban Site of Sarazm, which belongs to the Silk Road UNESCO Program, shares with The Ancient Walled Oases of Northern Arabia a very ancient history shedding light on early stages of human sedentarisation around the 4^th and 3^rd millennia BCE, the development of irrigation skills and industrial activities related to metallurgy, and a common trading role constituting a bridge between the surrounding regions of Central Asia. The serial property displays similar dynamics but bear witness to a sensibly different narrative, embedded within a different regional context. The successive layers of civilizations displayed in The Ancient Walled Oases of Northern Arabia-scape tell a different story, where the Frankincense Road is as central as the Roman occupation and the Islamic conquest. Through these features, the property provides a unique testimony and adds a new narrative to world heritage.

The construction of monumental walls all around the oases constitutes the final and most impressive specificity of the series, which is closely related to the two previous points. This indigenous technology played a critical role against the erosion of the cultivated soils and their devastation through blown sands, floods, and other natural hazards. While the Bronze Age Archaeological Sites of Bat, Al-Khutm and Al-Ayn in Oman display remarkable efforts to protect the palm groves and the human settlement, through the erection of monumental towers and localized walls, the north-western Arabian oases display a protection ambition which is not restricted to defence against armed attacks, but also aims to adapting a hostile environment and enhancing their visibility by international merchants to fill their role as intermediary commercial stations.