The Nullarbor ‘karst’ is the largest arid area of limestone in the world. It has many hundreds of caves.

The roof of Cocklebidy Cave has collapsed, revealing a system of massive underground caverns and more than six kilometres of underwater passages. The entrance to the cave is an perfect example of a collapsed ‘doline’.

Since the 1960s Australian and international teams have made numerous cave diving expeditions, gradually pushed further into the cave, setting new world records for cave diving distances. Read more about these brave, calculated attempts here.