Fossil Cave

Fossil Cave
The Green Waterhole, 5L81
LocationPrinces Highway, Tantanoola, South Australia, Australia
Coordinates37°43′55″S 140°31′52″E / 37.7319°S 140.5310°E / -37.7319; 140.5310
Depth15 metres (49 feet)
Length70 metres (230 feet)
GeologyOligocene coralline limestone
Entrances1
DifficultyAbove water - no stated difficulty
Underwater - CDAA Advanced Cave grade
Hazardssilting, overhead environment
AccessAbove water - public (no disabled access).
Underwater - CDAA members only.
Cave surveyFUUC, 1978
Allum and Garrad, 1979
SAUSS, 1987
Horne, 1986-88

Fossil Cave (5L81), formerly known as The Green Waterhole, is a cave in the Limestone Coast region of south-eastern South Australia. It is located in the gazetted locality of Tantanoola about 22 kilometres (14 miles) north-west of the city of Mount Gambier, only a few metres from the Princes Highway (Route B1) between Mount Gambier and Millicent. It is popular with cave divers and is notable for being both a unique paleontological site and the "type locality" for very rare crustaceans (syncarids - Koonunga sp.) which to date have been found only in caves and Blue Lake in the Mount Gambier region.