Neptune’s Grotto is a remarkable series of caves just outside Alghero, which can be seen on a 45-minute tour. Boats leave from the marina, and the hour-long journey takes in the dramatic coastline surrounding the limestone headland, Capo Caccia. You can also catch a bus to Capo Caccia and climb down the 654 steps to reach the caves below.

Opening Time: Daily 9am to 7pm (April to September); 10am to 5pm (October); 9am to 2pm (November to March)