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Precolumbian chiefdom settlements with stone spheres of Diquís

Date of Submission: 26/09/2012
Criteria: (i)(iii)
Category: Cultural
Submitted by:
Permanent Delegation of Costa Rica to UNESCO
State, Province or Region:
Osa Canton (County), Province of Puntarenas
Ref.: 5782
Word File

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Property names are listed in the language in which they have been submitted by the State Party


More than 45 archaeological sites with stone spheres have been recorded in Southern Costa Rica. They represent a particular stage of cultural development, pre-Columbian chiefdoms in the tropical rainforests of Southern Central America, with a very distinctive artifact: the stone sphere.

A group of these sites, Finca 6, El Silencio, Batambal, Grijalba and Canlo Island, has been selected to be nominated for its declaration as World Heritage. These sites are located in the Diquís Delta, which is crossed by the northern parallel 9°00 and the western meridian 83°30.

The territory of these sites together covers an area of 15 ha. One site, Finca 6 is located in the delta's floor, three of them (El Silencio, Grijalba and Batambal) in the piedmont, and one (Cano Island) in an island.

For several years a research, conservation and management project for these sites has been developed by the National Museum. Nuclear areas have been identified and, in the cases of Finca 6 and Batambal Archaeological sites, acquired by the National Museum. Cano Island is a special case, since the whole island is a natural reserve, under State control. Currently the acquisition of the nuclear archaeological areas of Grijalba and El Silencio sites is being carried out on an accelerated basis, since both sites are located in private properties. In all cases, the legal measures for the protection of archaeological vestiges, in accordance with national law, are mandatory. The National Museum monitors the state of preservation of these archaeological sites several times a year.

The general information and geographical coordinates of the sites included are:

Finca 6 site (N8 54 41 E83 28 39) is located in the alluvial plain next to a creek subject to inter­tidal action. It was part of an extensive deposit of sedimented material that covers the Diquís Delta. The area has been used extensively for banana plantations since the 1940's. At this site, two stone spheres alignments, several artificial mounds, one of them with associated store spheres, burials, pavements and debris deposits have been recorded.

El Silencio, (N8 57 04 E83 26 28) is an extensive site where the biggest stone sphere recorded yet (2.5 m. in diameter) is located. This sphere is placed at the slopes of the Coastal range, near a pre-Columbian cobblestone pavement. The sphere was damaged by human made fires some decades ago and presents exfoliations.

Batambal, (N8 58 08 E83 28 37) is a site located on a hilltop along the Terraba River. It covers approximately 2 hectares. Here four spheres have been located, associated to material deposits, artificial mounds and diverse structures built with cobblestones. This place has an excellent view of the Delta's plain, the Pacific Ocean and the surrounding mountains.

Grijalba, (N8 58 55 E83 31 22) is a site located in an upper terrace of the Balsar River, a tributary of the Terraba River. In this settlement there is a sphere associated with material deposits, artificial mounds and pavements built with cobblestones that cover an area of approximately three hectares.

Cano Island, (N8 43 00 E83 54 00) is located about 17 miles northwest of Punta Llorona in the Osa Peninsula. The island has an extension of 3 km long in east - west direction, and a width of 1.5 km, for a total area of 200 hectares. There is evidence of at least two different periods of occupation. 17 different archaeological localities have been recorded, as well as two small sized spheres.

Justification of Outstanding Universal Value

Criterion (i): The late pre-Columbian chiefdom societies of southern Cost Rica manufactured stones spheres, a particular and unique monument of almost perfect sphericity. They have been found throughout the area either isolated or in groups that form alignments or geometric figures. They range in size from 7 cm to 2.5 m in diameter and between a few kilograms to over 15 tons in weight. They were located in open areas, probably plazas, in front of principal residences or in special locations. Because of their number, sizes, finishes and contexts, these artifacts are considered unique.

Due to their almost perfect roundness, technology, skill and knowledge of raw materials implied and the level of abstraction and symbolism they show, the stone spheres and their locations and contexts are masterpieces of universal value.

Criterion (iii): Chiefdoms are ranked or hierarchical societies and are considered the stage of social development previous to the State, therefore a fundamental step in the development of Mankind. They present great diversity. Chiefdoms that inhabited the tropical area of the Diquis region developed settlement hierarchies reflecting the domination of large territories and their resources. They are also examples of societies that did not exploit the natural resources to the extreme. The archaeological sites with stone spheres of southern Costa Rica are a testimony of the pre-Columbian chiefdoms characteristic of Southern Central America.

The selected group of archaeological sites from the Diquis are considered to represent this particular level of social organization. They present plazas, circular mounds with porches and access ramps associated with stone spheres, a unique monument that was used as symbol of rank and ethnicity along with other elements such as zoo and anthropomorphic stone sculptures, gold ornaments and pottery. There are also, rectangular burial mounds, spheres alignments and areas with abundant waste.

Statements of authenticity and/or integrity


The authenticity of the archaeological sites included in this proposal is based on several physical, written and figurative sources of information which make it possible to know the nature, specificities, meaning, and history of this particular cultural heritage.

Documental: The chronicles of the Spaniards of the XVI century relate the presence of indigenous occupations that built elevated structures (cobblestone mounds). They also describe the configuration of the settlements, and a complex social organization capable to mobilize population for the building of public works.

Physical: the archaeological excavations and different studies performed for several decades have produced results to document contexts and the stratigraphic positions of the structures and materials that can only be assigned to the pre-Columbian period.

Form and design: ceramic, stone implements, gold artifacts and bone tools present forms and designs only recorded for pre-Columbian times. Style variations indicate several periods of occupation.

Materials and substance: the use of gold, pottery, stone and bone from tombs and dwellings correspond to a period predating the introduction of other materials such as iron, glass, metal by the Europeans. The impact of conquest and Colony caused the disappearance of the use of materials and techniques.

Use and function: the use of funerary offerings changed with the imposition of Christianity. The techniques,  raditions and use of tools and domestic utensils made of bone, stone and pottery changed with the imposition of new materials and ways of life on the XVI century.

Location and setting; the use of certain areas such as hilltops for villages and cemeteries changed with the new patterns established by the Spaniards.

Radiocarbon dates: several radiocarbon dates establish a chronological framework based on materials and structures, which establish an age before or during the arrival of the Spaniards in the XVI century.


The integrity of the properties nominated under criteria i and iii must be in good condition, and the impact of deterioration processes controlled.

Despite many years of looting and extensive agriculture works in the Diquis delta and surroundings, recent excavations have proved that many archaeological structures and contexts are well preserved under thick layers of sediment or in hilltops surrounding the delta.

In the delta's floor, the cyclical floodings have deposited at least 1 m of sediments on top of ancient occupations during the last five hundred years. This has produced "sealed" contexts in those areas not affected by drainages or other activities that involve deep excavations.

In sites located in the piedmont, significant groups of structures are well preserved, while others present partial damages by looting and agricultural activities.

A significant proportion of the elements necessary to convey the totality of the archaeological value of the properties remain in each site. Despite the partial damage by looting or agricultural activities, it is possible to reconstruct the plan of the whole settlements with the remaining portions.

Concerning the stone spheres, during the central decades of the XX century dozens or hundreds of them were removed from their original locations to other areas within the country or abroad. The sites included in the nomination still have spheres in their original position and are subjected to protection and conservation measures.

At Finca 6 Archaeological Site, two alignments of stone spheres remain in their original locations. Additionally, two spheres are located in front of a ramp associated with an artificial mound. One of them was recovered several years ago and moved to a place nearby, since the property was not owned by the National Museum at that time. It is being moved back to its original place. The other is in its original place.

There are large remains of two main structures at Finca 6, well preserved despite some looting and cuts by drainages. They are circular mounds of 30 m of diameter with porches and ramps.

Four stone spheres at Batambal Archaeological Site are associated with partially preserved structures made with cobblestones. Three small spheres have been found in situ at Batambai site in a partially preserved structure and associated with a great quantity of fragmented sculptures.

The largest stone sphere found to date in the Diquis region is preserved in El Silencio Archaeological Site, although decades ago it was partially affected by fire, due to the extended practice among farm owners in Costa Rica, in the past, to use fire to clear fields before cultivation. A paved area is associated to the sphere, of which more that 50 percent is preserved.

There are very well preserved structures at Grijalba Archaeological Site, as well as one sphere in its original position.

Comparison with other similar properties

In terms of archaeological sites declared as World Heritage Sites, we can compare in a first level with the nearest archaeological sites declared as World Heritage. The nearest is Jaya de Gerén Archaeological Site (World Heritage Site, 1993) in El Salvador. The site, a Classic Mayan domestic village, is preserved under layers of volcanic ashes. The Committee inscribed the site under criteria (iii) and (iv) and declared. "Joya de Ceren was a pre-Hispanic farming community that, like Pompeii and Herculaneum in Italy, was buried under an eruption of the Laguna Caldera volcano c. AD 600. Because of the exceptional condition of the remains, they provide an insight into the daily lives of the Central American populations who worked the land at that time". (http://whc.unesco.org/en/list/675)

Comparison with the settlements from the Diquis can be done in terms of size and level of complexity. Also, we can establish a parallel in the effect of volcanic ashes in Joya de Ceren to the impact of sediments that covered the Diquis delta and "sealed" human activity areas and structures. However, this comparison would be biased because the site corresponds to a different cultural area, Mesoamerica. In this sense the sites with stone spheres from the Diquis are representative of a cultural area which is poorly or not represented in the List.

A more feasible comparison is with the San Agustin Archeological Park (World Heritage Site, 1995), in Colombia. San Agustin has "The largest group of religious monuments and megalithic sculptures in South America stands in a wild, spectacular landscape. Gods and mythical animals are skilfully represented in styles ranging from abstract to realist. These works of art display the creativity and imagination of a northern Andean culture that flourished from the 1st to the 8th century ". (http://whc.unesco.org/en/list/744)

San Agustin and the Diquis Delta are in the same macro cultural area, the Isthmus-Colombian Area or Chibchan-Choca Area as it is also known. They present examples of megalithic sculptures, and the structures (artificial mounds) present some similarities, but spheres represent a type of sculpture unique in their own. The sites with stone spheres are located in the isthmian section of the macro region, where there are no archaeological sites included in the List. Moreover they represent chiefdom societies in their particular isthmian variation. The proposed group of sites presents more regional variation, since San Agustin is a single site.