
It starts in the area of Frosinone from the confluence between the Liri, which first crosses Abruzzo and Lazio, and the Gari, which rises at Cassino and is often called Liri-Garigliano.
With a surface of over 1500 square kilometers, the limestone massif of Matese stretches between Molise and Campania and falls within the territory of four provinces.

It is one of the favourite stopping points in the long spring migration from Africa to Central Eastern Europe on the Tyrrhenian route.

For the ancient Italic peoples it was a sacred river. On the shores, they erected sanctuaries such as the Demetra and Teano one.