Monti Ernici

The Monti Ernici (Italian: "Mountains of the Hernici") are a mountain range in central Italy, part of the sub-Apennines of Lazio. They are bounded by the valley of the river Aniene to the north-east, that of the Liri to the east, and, from south to west, by the valleys of the and Sacco. They are the natural border between two central Italian regions, Lazio (north-east of the province of Frosinone) and Abruzzo (central-western province of L'Aquila).
The peaks have an average height of 2,000 m, the highest being the Mount Passeggio (2,064 m).
At the base of the Ernici Mounts is the cave of La Foce with a spring outflow in the Aniene river.
Etymology.
The mountain range takes its name from the Hernici, an ancient Italic population of Osco-Umbrian language who lived in the area.