Odysseus Cave

On the southern coast of Mljet, a short walk from the village of Babino Polje, a stretch of limestone hides one of the more unusual sights on the Dalmatian coast: Odysseus Cave. Its official name is Odisejeva špilja, though locals often just call it "Jama" (pit) — a fitting nickname, since the cave's roof collapsed long ago, leaving what looks from land like a deep hole cut into the ground.

What actually happened underneath is more interesting. The collapsed vault opened onto a chamber connected to the sea by a narrow, tunnel-like passage only 4 to 5 meters wide. There's no dry way in — you swim through the tunnel or paddle in on a small boat, and you'll want to come around midday, when the sun sits high enough to send light straight down through the water and turn the inside of the cave a deep, glowing blue.

The name comes from a local legend tying the cave to Homer's Odyssey: the story holds that the nymph Calypso kept Odysseus here for seven years before the gods finally let him go, and some islanders will tell you Mljet is the Ogygia described in the poem, pointing to the same olive groves and vineyards along the shore that Homer mentions. Whether or not you buy the myth, the cave is worth the detour on its own. Because it sits right on the water and can only be reached by sea, many charter guests exploring Croatia anchor here for the afternoon, swimming into the tunnel before the light changes.