 They are the oldest caves in the world.There are a number of speleothem structures in the cave, known by names such as the "Lowveld Rocket", "Samson's Pillar", and the "Screaming Monster"; some have been dated to 200 million years old.There are also microbial fossils of a cyanobacterium known as "collenia" in the rock; these formed 2000 million years ago.