Ruins of Rocca Calascio, a mountaintop fortress or rocca in the Province of L'Aquila in Abruzzo, Italy. At an elevation of 1460 metres, the Rocca of Calascio is the highest fortress in the Apennines. Built of stone and masonry exclusively for military purposes and intended only to accommodate troops and never as residence for nobles, the fortress overlooks the Plain of Navelli at one of the highest points in the ancient Barony of Carapelle, Abruzzo, Italy