Abstract—In three field seasons, the Roman towns Falerii Novi and Interamna Lirenas (Lazio, Italy) were surveyed using ground-penetrating radar (GPR). The aim was to take maximum advantage of the high resolution capability of the GPR technique. Beside the choice of the antenna frequency, unaliased data recording is important when undertaking a fullresolution GPR survey. In this project, the use of a GPR array allowed a high sample density (~0.05 m in in-line direction, and ~0.06 m in cross-line direction). The accuracy and precision of the positioning by means of an RTK GNSS and a robotic total station nearly fulfilled the requirement that the accuracy and precision should be better than half the required sample density (in this case ~0.04 m). The data were 3D migrated, which improves the lateral resolution. The results of the survey contributed to the understanding of the investigated Roman towns and their early development. For example, private houses, revealed in detail, confirm the existence of a regular pattern of land allotment.