Cleft Island, also known as Skull Rock, is a granite island located off the coast of Wilsons Promontory in the state of Victoria, in Australia. It belongs to a group of three islands called the Anser Group, and is one of the most picturesque of all islands in Wilsons Promontory.
The western side of the island has a gigantic cave with a grassy floor, that was probably carved by the sea when the sea levels were much higher, thousands of years ago. The cavern is 130 meters wide, 60 meters high and 60 meters deep. From a certain angle, the island looks like a skull – hence the name Skull Rock – complete with a big cranium, an eye socket (the cave) and the bridge of a nose. The cave was once thought to be used as target practice by passing ships.