In contrast to the iron-rich and orange-tinged sandstone found throughout the rest of the area, Wedding Cake Rock is a light calcareous. Its peculiar form is the result of an original fortuitous formation and millions of years of erosion. Take the ferry to Bundeena from Cronulla. Follow the signs to the Royal National Park once there and follow the route ' Coastal Walk.' It's about 3 km (1.8 miles) from the start of the walk. Wedding Cake Rock is unstable, with a fence around it now. Staying behind the closed-off areas is a good idea. Standing or sitting on the edges of the rock or cliff is a very high safety hazard. Come in at your own risk.