Božidar Slapšak / Gašper Rutar
(University of Ljubljana, Ljubljana, Slovenia)
The outstanding results of geophysical survey at the ancient city of Tanagra in Boeotia have been presented here, and published in the Enter the Past volume. Geophysics permits clear reading of the urban structure, also in relation to the city walls and the rhythm of the towers along the line of the walls, and identification of functional areas and public architectures such as the agora with the stoa and other buildings, gymnasium, baths, theater, and early Christian basilicas, but also of less conspicuous architecture including private housing within regular city blocks and locuses of industrial activity. The assumed area of major temple buildings on the terrace next to the theater is still to be surveyed. The rationale behind the groundtruthing procedure such as developed and tested in 2003 and applied on a larger sample in 2004, is based on the assumption of documentary value of both precise locational data, and of qualitative data pertaining to the surface structures. The site of Tanagra is not exactly rich in visible architectural remains: still, it was the study of these remains that permitted Roller to propose his reconstruction of the urban organization there back in 1987. Admittedly, his plan has to be corrected in many parts now, but it was a valuable attempt, and he identified the urban module and the basic structure correctly.
Since the same surveying grid is used for both geophysics and surface structures survey, locational data can be used as a powerful feed-back for geophysical survey, and the geophysical map will permit complementing the very fragmented information of the surface architecture. The use of GPS permits to easily locate in the field the key points such as the crossroads and the crucial points in architectures observed, as read on the geophysical map. Even within the limited area of eight city blocks (4 ha), relational analysis of information layers, including qualitative data on surface structures, permits observations on phasing and rebuilding, on metrology and on inconsistencies in laying down the grid (typically, there will be some deflection on the lines which cross the main ridge hindering visual contact between the corners of the city blocks). Parallel to that, surface morphology survey and architectural fragments surface survey is being done in areas of special interest, adding further layers of information, and supporting interpretation of the data mapped.