Glacier Rock, also known as Selwyn’s Rock, is a ~280 million year old Glacial Pavement carved into 510 million year old bedrock, exposed in the Inman River bed below the cafe. This is the largest of several glacial pavements created on the Fleurieu Peninsula by the Permian Ice Age, and one of the largest glacial pavements in the world. The grooves, scratches and crescent shaped marks on the rock surface indicate the icecap moved from southeast to northwest here.

The riverbank above Glacier Rock contains boulders and rock debris dumped by the melting icecap, including granites from Victor Harbor.

The first European recording of Glacier Rock was in 1859 by ARC Selwyn, a geologist working for the South Australian Government. It was the first European recorded discovery of glaciations in Australia. It was then rediscovered in 1897 by famous geologists Sir David Edgeworth and Dr Walter Howchin, from Sydney and Adelaide Universities.

Glacier Rock attracts geologists from all over the world.