The Liri's source is in the Monte Camiciola, elevation 1,701 metres (5,581 ft), in the Monti Simbruini of central Apennines (Abruzzo, comune of Cappadocia).

[7] At the mouth of the Liris near Minturnae, was an extensive sacred grove consecrated to Marica, a nymph or local divinity, who was represented by a tradition, adopted by Virgil, as mother of Latinus, while others identified her with Circe.

[8] Her grove and temple [9] were not only objects of great veneration to the people of the neighboring town of Minturnae, but appear to have enjoyed considerable celebrity with the Romans themselves.

[10] Immediately adjoining its mouth was an extensive marsh, formed probably by the stagnation of the river itself, and celebrated in history in connection with the adventures of Gaius Marius.

The Roman emperor Claudius had a tunnel dug through the ridge in an attempt to drain the lake, which had no natural outlet, to the Liri.