Mljet lies south of the Pelješac peninsula, from which it is divided by the Mljet Channel. Its length is ; its average breadth . It is of volcanic origin, with numerous chasms and gorges, of which the longest, the Babino Polje, connects the north and south of the island. Port Polače, the principal harbour in the north, is a port of call for tourist ferries. Mljet contains one hotel—The Odisej (from the Greek Odysseus) in the north-west corner of the island.