3. Cagliari is the regional capital of Sardinia. The town is situated in southern Sardinia on the homonymous gulf, also called the bay of the Angels, surrounded by the Campidano plain and between Molentargius pond, and the lagoon of Santa Gilla. In common with Rome, Lisbon and Istanbul, Cagliari was built on 7 hills : Castle, Tuvu Mannu, Tuvixeddu, Monte Claro, Monte Urpinu, Colle di Bonaria, Colle di San Michele.