The landscape settings of the many monuments of the Carnac area are impossible to consider fully through fieldwork alone because of modern land use. Although there are some limitations in relying on GIS and visualisation to explore human experience of landscapes, these techniques provide an important contribution to our understanding of the Neolithic of the area. It is, however, likely that visibility was only one of a range of characteristics of the landscape which was considered to be important.
Digital analysis has shown that the locations chosen for the construction of different types of monuments had distinct landscape characteristics (Roughley 2001; 2002a). It is therefore possible to infer that the monuments were engaged with in different ways (Roughley forthcoming), which relate to different interactions between people and their surroundings.
Visibility analysis is an important tool for understanding this landscape, as it is impossible to assess the visual characteristics of site locations in the field. Although the technique has its limitations, it is possible to expand our understanding of the locations of the earthen long mounds. These monuments were not only non-randomly in space, but moreover were distributed within a landscape which was divided visually into different areas, with clusters of inter-visible monuments. Different scenarios for the use of the landscape can then be proposed (see Roughley forthcoming). The use of individual viewsheds, rather than relying solely on a cumulative viewshed analysis, has allowed much greater flexibility in the consideration of the landscape setting of the earthen long mounds.
Analysis of the locations of the angled passage graves has demonstrated the importance of accurate archaeological data, in this case monument height. This is particularly the case in such a topographically subtle landscape. Visibility analysis shows that small changes in monument height would have had significant impacts on the visibility of the site.
The use of visualisation software can further expand our understanding of the visual characteristics of locales. Visibility analysis has shown that the angled passage graves may have been visible from the river. However, the visualisation demonstrates that this was not necessarily the place from which some of them, particularly Le Lizo, were most easily seen. The more subjective approach of dynamic visualisation allows the viewshed analysis to be placed in context. It considers visibility not as a set of binary opposites but as a complex phenomenon, albeit with some limitations.
It has been speculated that the choice of locations for angled passage graves may have in part been influenced by a desire to maintain links with areas of the landscape which were of particular significance in earlier periods. However, the provision of a VRML model means that further explorations can now be undertaken by you. Although less accurate than the original model, the VRML version provides much greater accessibility, and such models are likely to play an increasingly significant role in the wider consideration of archaeological landscapes in both research and management.
The combination of visibility analysis, an 'objective' technique, with visualisation, a very subjective approach, allows the complexity of the visual settings of the monuments to be explored more effectively. It is considered that, through the use of a range of complementary techniques, a fuller understanding of the Carnac landscape has been obtained than would have been possible through the use of any single approach. Ongoing research complementing virtual reality approaches with the use of 19th-century illustrations is providing an additional, but possibly very subjective, perspective on this landscape (Roughley 2002b; Sherratt and Roughley forthcoming), with its own theoretical difficulties.
GIS and other computing techniques do not determine the kinds of archaeological interpretations which their users formulate. While such techniques may bias the lines of enquiry pursued (including encouraging consideration of vision rather than other senses), this does not determine how the results are then used to come to archaeologically significant conclusions. By increasing the variety of approaches used, further insights into the archaeological questions we are considering are likely to be forthcoming.
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Last updated: Thur Nov 11 2004