The Etruscan city was built on two adjacent plateaux, to the west the Pian di Civita and to the east the Pian della Regina. Integral part of urban topography is also the cone shaped hill of Castellina, at north-east of the Pian della Regina, included in the fortified walls and, because of its prominence, hypothesized as the town acropolis.

Overall, the urban topography, in its various chronological phases, is little known because the city has so far been only partially excavated by the Università di Milano (particularly it was discovered on the Pian di Civita a large religious complex dating back to Villanovan and Orientalizing periods).
Anyhow it has been possible, at least on the Pian di Civita, to find the traces of a regular city plan probably to be referred to the Classical period.

(from M. Cataldi, Tarquinia, Regione Lazio 1993)