1. Calanques National Park, France
These rocky cliffs between Marseille and Cassis aren’t the easiest to get to, but the swim that awaits is worth every bead of sweat lost on the hike. Les Calanques is known as the natural wonder of Provence for good reason, and the two ocean inlets (Calanque de Port Pin and Calanque d’En Vau) within are just about as idyllic as it gets. Go in the morning to make the most of it because these secluded spots get busy in summer.