Once known as Lake of Carinola, it is a volcanic lake at the foot of mount Massico, in the municipality of Falciano del Massico.

It rises at the foot of Mounts Trebulani, at 86 meters above sea level, in the territory of Calvi Risorta.

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.

It is an artificial lake, created in the 1960s to power the electricity station of Capriati al Volturno.

The longest river of Southern Italy with its 175 kilometres rises in Molise, at Rocchetta a Volturno and runs for a long way in the Apennine region, of which, after the Ponte 25 archi, marks the border with Campania.

On its shores violets grew, and this is why the Greeks called it Clanis. The River Clanis rises on Mounts Tifatini.