(Laboratory of Geophysical-Satellite Remote Sensing & Archaeo-environment, IMS-FORTH Rethymnon, Greece)

Past travelers and excavator researchers provided a number of descriptions and sketches of the ground plans of monuments existing in various archaeological sites. Faced with a lack of appropriate instrumentation they produced them with a questionable accuracy and detail, although they are still used by archaeologists as a guide for their excavations and interpretations of the archaeological sites, especially in cases where the particular monuments have been covered again by soil. Geophysical prospection techniques are able to provide further evidence of the verification of such plans and test their degree of accuracy. Furthermore, they can attest older excavation diaries describing details of the interior of the monuments.
Examples will be drawn by various geophysical prospection campaigns in Greece, mainly from Axos, Chersonissos, Sikyon and Dodoni. In Chersonissos (Herakleion), Onorio Belli’s (1550-1603) description and plans reported that the Roman theatre presents enough originalities compared to the rest theaters of Crete. The site was surveyed through combined magnetics, GPR and ERT techniques and their fused interpretation was compared to the rectified plan of Belli. Similar kind of plans, accompanied by photographic evidence, exists for the Archaic/Hellenistic temple of Aphrodite in Axos (Rethymno). The material is coming from older excavations of the Italian Archaeological School (Levi 1930-1) and was compared to the geophysical maps resulting by the GPR, soil resistance and magnetic surveys. In Sikyon (Peloponnesus), the geophysical data were cross-checked with the descriptions of Pausanias and the simplified excavation plans made by the American School of Classical Studies in 1890s and early 1900s and by the Archaeological Society (1920s-1950s and in the 1980s). In a related example, soil resistance and magnetic surveys were able to correct and complete the plans of the ancient agora of Dodoni (Epeiros).
In all cases, the written testimonies and plans of the archaeological sites proved valuable in guiding the geophysical surveys, which on the other hand were able to verify the accuracy of them and complete the mosaic of the architectural details enclosed.

Keywords: Geophysical prospection, topographic plans, magnetics, GPR, soil resistance, Greece