Magnetic, resistivity and ground penetrating radar prospection surveys were carried out inside the Roman Agora of the ancient settlement of Delos (Fig. 1). Magnetic and soil resistance data were processed through the use of high pass filters, directional derivatives and compression of the dynamic range of the original measurements. A high correlation between the magnetic and resistivity maps suggested a few candidate targets. In GPR survey, CMP measurements suggested that the velocity of propagation of the acoustical waves in the area of study approached the value of 0.062m/nsec. Parallel transects were scanned through the use of 450MHz and 225MHz antennas providing information about the vertical stratigraphy of the site. Various processing procedures, such as time-slicing, 3D visualization and animation techniques were used for enhancing the resulting image. The extraction of 3D extent information was achieved through a synthetic volumetric modeling, visualized through the calculation of isosurfaces that represent the intensity of reflection of the EM wavelets. A number of candidate targets have been suggested, one of which may coincide to the location of an older back-filled excavation trench. Other targets may represent the remnants of architectural monuments within the Agora.