Homer’s Odyssey says that King Odysseus, after surviving a shipwreck, swam to an island which belonged to the nymph Calypso, who lived in a cave. She was enamored with Odysseus and wanted to marry him. He therefore became her prisoner for several years until Athena asked Zeus to have him released. Calypso finally conceded and let him go. Local folklore states that this is that very cave where she lived. However, no one really knows the location of this island (named Ogyia in The Odyssey) or its cave, if it indeed exists at all.
Mljet is the most southerly and easterly of the larger Adriatic islands of the Dalmatia region of Croatia.