They were made using such huge blocks of stone, that for many years their construction was attributed to mythical giants, the Cyclops, or to the legendary population of the Pelasgians.

They are very difficult to date accurately, but it seems certain nowadays that the most ancient polygonal walls -  as they are called today owing to the more or less irregular shape of the stones used – that they date back to at least the 7th C. b.c.

The polygonal walls that stand on the plane that overlooks modern Artena delimit an ancient city. We don’t know its name, but it could be the ancient Fortinum.

The walls of this fortified city, 2.5 km in length, are a rather basic polygonal construction, with large stones that are very rough-hewn.

They encircle a fairly considerable area (approximately 800 metres long by 500 metres wide) inside which traces of a few terraces, roads and cisterns have been found.