The Rock Islands are ancient relics of coral reefs that surfaced to form the 250 to 300 islands in Palau’s Southern Lagoon. The islands are for the most part uninhabited, and are famous for their beaches, blue lagoons and the peculiar shapes of many of the islands. The Rock Islands are also home to the famous Jellyfish Lake, a lake with jellyfish with very weak stingers where snorkelers can safely swim.