New discovery of an ancient building in Akragas (Valley of Temples, Agrigento, Italy) through the integration of geophysical surveys

The integration of geophysical methodologies applied in an unexplored area of the Valley of the Temples, in the ancient Akragas (ancient name of Agrigento), has led to the exciting discovery of buried building remains. The study site, situated north of Plateia I-L, is largely unexplored and considered to be rich in archaeological remains. The site, approximately 3.000 m 2 , was divided into four sectors and investigated by using not invasive geophysical surveys, including extensive Electromagnetic techniques (EM) and Electrical Resistivity Tomography (ERT). For the Electromagnetic surveys, a multifrequency electromagnetic device with a frequency range of 2.5–250 kHz was employed. As for Electrical Resistivity Tomography (ERT), a multichannel georesistivimeter MAE X612-EM was used. Through the integration of data obtained from both techniques, a comprehensive analysis was conducted, revealing numerous subsurface anomalies indicative of buried structures, given their shape, size, and physical characteristics. Subsequent archaeological excavations, carried out in the areas where the geophysical anomalies were detected, unveiled the presence of a wall constructed with large blocks of local calcarenite. Subsequently, the wall was scanned using photogrammetric techniques to obtain a sharper 3D reconstruction with greater detail. Preliminary analysis suggests that this wall belongs to a building possibly dating back to the Hellenistic or Classical period. Such a find probably represents only a small portion of a larger and more complex structure. Significantly, due to its proximity to the entrance of the “circular altars” sanctuary, this building could have played a vital role in the religious topography of Akragas.