The Green Waterhole (Fossil Cave) is a cave located near Tantanoola.The cave is valuable for palaeontology and cave diving enthusiasts primarily because it’s within a 30-million-year old Oligocene coralline limestone cave.
Its distinguishing feature is the karst sinkhole; most of which is filled with water.
Cave diving activities at the Green Waterhole are restricted to advanced-level members of the Cave Divers Association of Australia.