Reaching Porta Nova, one of the last gates of the city of Tarquinia to be built, you can enjoy an extraordinary view, as well as discover the charm hidden behind the city walls and defensive system.
The first phase, characterized by regular rectangular macco ashlars set directly on the exposed rock, develops around easily accessible areas; it corresponds to the expansion of the city, beyond the castle, into the Poggio and Valle districts (9th–12th centuries). The second phase corresponds to Castro Novo. The ashlars are smaller than those of the previous period, and the defensive layout is characterized as a military system with a moat. The incorporated towers, along with some within the city, served as lookout points.
Numerous service postern gates at the access points, some with a bayonet structure, retain their original form (Porta di Castello), while others result from various interventions (Porta della Maddalena).
The layout has also undergone transformations due to changing urban needs. Notable are some extra-mural towers, no longer in existence; it is undoubtedly significant that in the fresco depicting the genealogy of Corito, located in the Sala degli Affreschi of the Town Hall, the defensive system of Corneto appears, overall, as it is today.