The research program carried between 1983 and 2003 by the École française de Rome, in strong partnership with the Soprintendenza archeologica per l'Etruria meridionale, on the hellenistic and roman site of Civita Musarna (Viterbo), has brought new, concrete light on the Etruscan urbanistic conceptions.

Through archaeological excavations and geophysical prospections, it was possible to restitute, for the first time inside the classical territory of Etruria, the overall urbanistic grid ot a city. It was founded as an internal colony of Tarquinia at the end of the IV century BC to counter the Roman threat, and later occupied, apparently  continuously, until the beginning of the VII century AD.

The city lies on a ca 5 ha tufo plateau, which was divided according an ortogonal grid forming twelve blocks of houses, each of them himself divided in three sections, and lined up along a main street, which widens in its center in order to create a large rectangular square. This accurate planning was duplicated, under the ground level, by infrastructures which reproduce the urban grid (public and private sewers), or were created to answer the needs of its inhabitants (cisterns, silos).

The overall, inclusive datas gathered on the city - dimensions of the house blocks, of the public and private constructions so far excavated, ranges of the tufo blocks  used to build the city, but also its defensive walls and its burial monuments - allows to restitute the gromatic principles which were in use at the moment of the city's foundation, and to identify various modules, some of them dating back to the originary phase, others used later in order to modify, sometimes in a meaningful way, the assett of the city planning. They can be compared with datas collected from other sites, in order to valutate how specific the city was in the larger frame of the Etruscan world.