Skull Rock, formally known as Cleft Island, is a small, but remarkable granite island that sits among the Anser group of islands off the southwest coast of Wilsons Promontory, Victoria, Australia.

The island lies within the Wilsons Promontory National Park. Due to the position of the island, high winds and ancient waves have carved out a fascinating 130-meters wide, 60-meter tall cave that sits in this hollowed-out cavern. The rugged formation can be seen from the coast, but it is only from up close on a boat that the island can truly be appreciated. 

The island is also a site of great natural significance because of the number of breeding seabirds who choose to nest inside the deep, sheltered cavern. There is also a large fur seal colony that can be found perching on the granite structure and nearby islands. Surrounded by the waters of the Bass Strait, the sheer magnitude and unique shape of the island make it one of Australia’s most interesting natural formations. 

Little is known about the history of the island, but it is said that more people have been on the moon than inside Skull Rock. Due to the precarious cliffs and surrounding waves, the climb up the slippery rocks would be rather treacherous and local records suggest that only nine people have been inside the deep cavern.

In a recent expedition involving Neil Oliver, Scottish television presenter, a team landed on the island by helicopter and abseiled down into the grassy cavern. They found old decaying cannonballs, which local historians believe were a result of passing ships using the rock formation as target practice over the years.