The route goes from north to south with the first stop at Norchia, an ancient site inhabited since the Palaeolithic period.
During the Etruscan period, it was a centre gravitating in the orbit of Tarquinia and developed between the 4th and 2nd centuries B.C.: in this phase, the characteristic rock necropolises excavated in the tuff were created, in which the prevalent type of tomb was a dado or semidado tomb.
The three main necropolises are developed along the sides of the valleys carved by the three watercourses: the Fosso Pile (Prostyle Tomb, Three-Headed Tomb, Smurinas Tomb), the Acqualta ditch (Temple or Doric Tombs) and the Biedano stream (Lattanzi Tomb).
We continue on to Blera, a Roman centre which expanded the most in the Etruscan period. The eastern necropolises, including that of Terrone, are particularly interesting.
In the nearby locality of Barbarano Romano is the S. Giuliano necropolis, included for its naturalistic interest in the Marturanum Regional Park.
This archaeological area is one of a kind because it offers a complete panorama of the development of Etruscan funerary architecture, presenting a typology that ranges from the pit and pit tombs of the Iron Age to the large orientalising tumuli, from archaic rock tombs to Hellenistic dado tombs: descending into the bottom of the gorge will feel like travelling back in time, from the 7th century B.C. to the 3rd century A.D.
The visit can be completed with a stop at the Archaeological Museum of the Rock Necropolis of Barbarano Romano.