Monte Cucco (1,566 metres), which retains important remains of the passage of the Romans, is the “Belly of the Apennines” with its complex hypogeous system, karstification phenomena and underground waters, which feed city aqueducts and mineral springs, and flow into the river Sentino. Here, fossils and unspoilt woods have been abandoned. The park is a favourite spot for sports such as gliding, caving and cross-country skiing.