There are places where the interplay between endogenous factors and morphogenetic agents builds up enchanting landscapes, suspended in a delicate condition between being an environmental resource or a natural hazard. When such places are also settled by the human presence, the final interaction is absolutely unique.
In Central Italy, past geodynamic and volcanic events together with the modelling of more recent exogenous processes have produced spectacular wide table landforms, like plateaus and smaller mesas and buttes, characteristic throughout the whole area. These mesas and buttes became shortly favourite and confortable sites for human settlements and, in times, for secure and defensible historic towns. Such ancient and often precious urban centres are continuously affected by natural hazards such as landslides that threaten their survival due to the strong geomorphological activity. The resulting scenery, where human modifications contrast and overlap the natural landforms acquires the value of a Cultural Landscape.
The town of Civita di Bagnoregio (Latium Region, Central Italy) — located at the border of the ancient Volsini volcano and placed on a high tuff peak that rests on fragile clay — is an exceptional example of preserved medieval village where successive cultural layers produced a harmonious ensemble of red tiled stone masonry buildings and stone paved narrow streets, set in a dramatically fragile and unstable environment. Civita is a stunning case where the human presence has tried for centuries to hinder the natural degradation of the cliff. It is a paradigm of the struggle of men aiming to survive in a hostile, though incomparably beautiful, environment, and nature that wants to take its course dismantling and eroding all reliefs. The town, of Etruscan or Villanovian origins (7th century BC), had a great expansion from the Roman Age to the late Middle Age, when the quarters Ponte and Carcere, (that have now disappeared) where added to the original urban nucleus. Topographical and cadastral maps, dating back to the beginning of the 18th century as well as other historical maps and documents, prove the progressive shortening of the cliff due to landslides that have caused, in different times, the destruction of portions of the town built on the cliff edge. Many historical records on occurred landslides and stabilisation works, since 1373 AD, have been collected and analysed in order to reconstruct in detail the evolution of the urban setting and cliff, where landslides repeating continuously throughout the valley are creating an ever-changing landscape that looks different every day.
The preliminary proposed perimeter defines a relatively small ensemble formed by the village, its tuff outcrop with the modern access bridge, and its surrounding visual basin where traditional agricultural activity continues to thrive. This area defines the cliffs that are impacting on the development of Civita. A large Buffer Zone guarantees the protection the larger setting of the property from unsuitable developments and preserves the views towards and from Civita. The proposed buffer zone that includes the badlands (the Valle dei calanchi) extending to the West behind Civita, also contributes to the property’s OUV with its important geological secondary attributes.
The Cultural Landscape of Civita di Bagnoregio, fully meets the World Heritage Convention definition of Cultural Landscape as combined work of nature and of man illustrative of the evolution of human society and settlement over time, under the influence of the physical constraints and/or opportunities presented by their natural environment. According to the categorization of cultural landscapes defined in the Operational Guidelines, the property constitutes an "organically evolved continuing landscape" (category II.2), which retains an active social role in contemporary society and in which the evolutionary process is still in progress. At the same time it exhibits significant material evidence of its evolution over time.
The Outstanding Universal Value of the Cultural Landscape of Civita di Bagnoregio lies in two distinct and complementary aspects relating on the one side to the exceptional features which testify the interaction between man and nature together with the quality and the state of preservation of its urban and architectural structures and on the other side to the unique geological characteristics of the site and to its ongoing rapid evolution.
The principal features and attributes that convey Outstanding Universal Value are:
1) The geological characteristics of the site lying on the border of the Volsini volcanic crater where a rigid layer of volcanic tuffs covers a plastic clay substratum, cut through by river erosion closely linked to the rapidity and relevance of the erosion phenomena on the site and their long lasting impact on the human settlement of Civita, whose very fragility and instability is due to the underlying morphology and geology of the area;
3) The unique record of the evolution and alteration of the soil over more than a thousand of years. Written and graphic historic sources detailing all landslides and collapses since the 11th century AD provide invaluable and unique data for the understanding of the evolution of the landscape;
4) The number and quality of the consolidation attempts realized throughout the last one hundred years to mitigate the impact of landslides. The multiple technical solutions applied in the territory of Civita offer a complete catalogue of soil consolidation techniques — from landscape interventions and tree plantations to contemporary high-tech anchors/nails and structural shafts — and constitute an exceptional historic document for the history of science;
5) The extraordinary architectural and urban quality of the medieval village perched on the hilltop, perfectly integrated into the natural environment in the surrounding of the hilltop village and rocky outcrop.
These attributes are reinforced by the quality and importance of contemporary technical interventions for the preservation of the site and by the high-quality management of the property aiming at its sustainable preservation. Evolving cultural landscapes are by definition not "static" and therefore their conservation implies identifying, understanding and managing — in a responsible and sustainable manner — the dynamics of the processes that influence their evolution.
Criterion (iii): The property bears a unique testimony to a cultural tradition which is living or which has disappeared. The Cultural Landscape of Civita di Bagnoregio proves the sustained relationship, over a long historic period, of human activity and human settlement on the one side and nature and a constantly evolving geological landscape on the other. This millenary tradition is doubled by a century-old tradition of scientific and technical studies and interventions that have contributed to the development of the science of soil consolidation (landslide science) in Italy and at the global scale. The extraordinary intensity and rapidity of geological decay in Civita di Bagnoregio provides an exceptional case study for the implementation of new consolidation techniques and for the scientific verification of their effectiveness. Particularly innovative for the evolution of consolidation science have been the first electro-osmosis consolidations carried out in Civita in the late 1950s, and the recently completed structural shafts cut into the hill rock.
Criterion (v): The Cultural Landscape of Civita di Bagnoregio is an outstanding example of a traditional human settlement and land-use, representative of the constants human struggle against a hostile and rapidly evolving geological environment threatening its very survival. The first historic written sources relative to the hydrogeological situation in Civita, and to the earliest attempts at stabilizing the site, date from 1373, when the Statuto Comunale forbade cutting trees to avoid landslides. Since, human actions to control natural erosion continued until the present with alternate fortune. Particularly relevant have been the interventions and the plans for the clayey access crest, where a series of projects — the older dating from 1764, others from the mid-19th century — were drawn, though not always implemented, to control the progressive sliding of the soil.
The Cultural Landscape of Civita di Bagnoregio demonstrates a very high degree of integrity at all the different scales composing the property:
- The landscape composed by the hilltop village, the surrounding valleys and nearby “bad land” valley shows a remarkable integrity and contains all the attributes demonstrating its OUV;
- The historic village of Civita and its surroundings are fully included in the property and are entirely preserved, materializing the historic depth of the property and the effect of geological evolution on the human settlement;
- The very geological basin producing the accelerated decay processes typical of this site is entirely protected and included in the property;
- The ensemble of the traces of the historic and contemporary attempts to consolidate and stabilize the property is preserved.
The integrity of the geologic and cultural ensemble has been enhanced recently through the active management of the site and the gradual restoration of the village of Civita under the supervision of the Municipality of Bagnoregio. The pedestrian bridge, though partially impacting on the visual and aesthetic qualities of the site, permits public accessibility to the village and is part and parcel of the history of the geological evolution of the site.
All the attributes of the property are contained within the proposed site boundary which is entirely included within the municipal border of Bagnoregio and is protected by the existing laws and regulations.
Civita di Bagnoreggio has been perfectly restored with methodologies and techniques in line with the ‘Restauration Charts’ recognized by the World Heritage Convention. Materials and substance and, as far as possible, use and function, were preserved. When new functions have been assigned, they respected the orginal heritage values.
The authenticity of the Cultural Landscape of Civita di Bagnoregio also concerns its very natural and geological features. The site has preserved its geological and historic physical appearance, with the traces of ancient and recent modifications caused by landslides, and with no contemporary traces of development apart from the technical interventions for the consolidation of the soil and of the rocky hilltop.
The anthropic landscape is dotted by traditional vernacular architecture and is still used for agriculture as in the past centuries showing a sustained authenticity of use.
The development of the village on the hilltop has been severely affected by erosion and Civita was largely abandoned after the 1695 landslide. Its urban layout has grown organically throughout the centuries and no incongruous modern construction affect the site. The urban layout and the architecture of Civita are fully authentic and carefully cared for by the residents. Legal protection mechanisms guarantee the respect of the highest conservation and restoration standards and preserve their authenticity. The recent re-use of some of the historic buildings as secondary houses and tourist accommodations has contributed to the revitalization and preservation of the property.
Notwithstanding the geological hazards, the inhabitants of Civita always refused to leave their village, even when the communal seat was moved to nearby Bagnoregio after the dramatic 1695 earthquake. Today the village is inhabited by few families of original permanent residents and by a growing number of new residents attracted by the architectural and urban quality of Civita and by its exceptional landscape.
The authenticity of the property, however, is also intimately connected to the "authenticity" of the ongoing struggle against landslides and collapses. Contemporary attempts and more ancient solutions are visible next to each other and form a unique and authentic representation of the art of architectural and soil consolidation. Interventions at different scales on the landscape of the property are visible and materialize the continuous efforts made for the preservation of a fragile status quo that constitutes the actual OUV of this property.
The continuous interrelation and adaptation of human presence in Civita di Bagnoregio and its surroundings with landsliding and erosional phenomena constitutes a première in the World Heritage context. No other World Heritage property provides this unique combination of urban, architectural and archaeological vestiges and of a unique geological formation actively erasing the human presence in an accelerated and partially unstoppable process of decay.
Landslides do affect a relevant number of municipalities and urban centres worldwide. Many Italian World Heritage sites are directly concerned, like Agrigento, or the Amalfi Coast, and this is the case also of a number of major properties across the world like Petra (Jordan), Machu Picchu (Peru), Easter Island (Chile) or Kathmandu (Nepal). However the value of these properties does not relate to the continuous interaction and fight for survival of a human community with the natural evolution of the landscape that characterized the history of Civita di Bgnoregio and constitutes its specificity.
At the national level, another set of comparison can be drawn with other Central Italy settlements, like Pitiglano and Orvieto, presenting similar conditions at the geological and architectural levels. These historic hilltop cities that developed on the borders of the same ancient centre Italian volcano, however, do not show the same magnitude of the geological phenomena that shape the Cultural Landscape of Civita di Bagnoregio; and their geology does not affect in the same way their urban and human environment. he geology of these sites does not affect in the same way their urban and human environment. The exceptional intensity and rapidity of the evolution of the geological landscape visible in Civita is unmatched in Italy and at the global scale, as it is unique the precise historic record of earthquakes and landslides over a millennium and of the attempts to control and stop the geological decay that characterize this property over more than a century.