Cala Battaglia

Drop anchor off Cala Battaglia, a striking black-sand cove sitting directly in front of the haunting ruins of Santo Stefano prison — one of the most dramatic backdrops you'll find anywhere in the Pontine Islands. The water is exceptionally clear, and the setting is quietly eerie, with the circular Bourbon-era penitentiary looming on the rocky islet just across the water. You can swim ashore or pick your way down via a steep path from the island if you prefer to stretch your legs on land.