Two connected saltwater lakes inside a forested island, warm enough to swim from May, with a 12th-century Benedictine monastery…Two connected saltwater lakes inside a forested island, warm enough to swim from May, with a 12th-century Benedictine monastery on an islet in the middle of the larger lake. You can kayak from the sea into the lakes. Croatia's greenest island to 90% forest. A 4th-century Roman palace stands at the head of Polače bay, its walls still 20m high, you anchor in front of it. Odysseus is claimed to have been held by Calypso in a cave on the south coast. Mljet became a national park in 1960, Croatia's first marine one. Anchorage: Polače is a superb all-weather natural harbour ringed by Roman ruins; moorings in the park. Hazards: No site-specific hazards noted, brief normally. More