The Ravine des Casoars is a steep sided valley of 3 kilometres (1.9 miles) length with an east–west alignment and with a maximum depth of 100 metres (330 feet).

[2] The ravine meets the sea on the west coast of Kangaroo Island via a gap of about 120 metres (390 feet) width in the coastline’s continuous cliff line.

The first known as ‘K5’ which accommodated at the time in this entrance, a little penguin rookery, was described as being 50 feet (15 metres) wide and as having a ‘massive rockfall’ and decoration including flowstone.

As of 1999, radiocarbon dating of material recovered via archaeological excavation from sites at Cape du Couedic and Rocky River to the south of the ravine’s catchment area suggest Aboriginal presence in the western end of Kangaroo Island from approximately 7,500 years BP to as recent as 350–400 years BP.

Baudin reportedly named the ravine after the numbers of the now-extinct Kangaroo Island Emu present at the time and which he mistook for the Cassowary.