Sinkhole reaching a depth of 32m at a maximum distance from the sinkhole of about 42m and it is considered to be fully explored. The groundwater within this system comprises a freshwater lens overlying a seawater wedge. The groundwater contains a remarkable assemblage of specialised subterranean fauna (stygofauna) including the only two species of blind fish known in Australia, the Blind Gudgeon and the Blind Cave Eel (both specially protected). The remaining fauna are predominantly crustaceans of various types including the remipedes.