We present the preliminary results of a geophysical investigation applied to the subsoil imaging of a morphological height (here described as mound) within the area of the ancient city of Gabii, situated 18 km to the east of Rome, and its near surroundings. Interpolated magnetic data revealed the presence of a dipolar magnetic anomaly in correspondence of the mound, which we interpret to be the response of a high intense magnetic sources, with a regular, almost rectangular, geometry, lying approximately at the base of the mound. In particular, forward magnetic modelling solutions suggest that this magnetic dipole could be presumably caused by a basal peperino plateau magnetized along the Earth's present-day magnetic fi eld. In the surroundings, magnetic results showed a series of intense dipolar magnetic anomalies, N-S oriented, arranged to form a linear road-like pattern which we attribute as due to leucititic lava stones buried at very shallow depth. Obtained results are encouraging. We believe that further geophysical investigations will be crucial to better characterize the inner structure of a potentially relevant archaeological feature.