Cleft Island belongs to the Anser Group of islands off Wilsons Promontory coast, Victoria in Australia. In the western part of the island there is a cavern that measures 30 meters in width, 60 meters in height and 60 meters deep and looks like a skull. For this reason the island is also known as Skull Island. In fact, there are two caves; the roof of the smaller cave forms the floor of the upper cave. The island is difficult to reach and those who have been there said that they found cannon balls inside the cavern.