Lookout · Limestone Coast

Mount Gambier is a maar volcano complex of four craters — Blue Lake, Valley Lake, Leg of Mutton Lake and Brownes Lake — believed to have last erupted a little before 6,000 years ago and considered dormant rather than extinct (https://en.wikipedia.org/wiki/Mount_Gambier_(volcano)) (Wikipedia)
The Blue Lake, a 75-metre-deep crater lake, changes colour with the seasons, appearing steel-grey in winter and cobalt blue in summer, and is a source of the city's drinking water (Wikipedia)
Mount Gambier's Blue Lake is 75 metres deep and hosts fields of large stromatolites, an unusual aquatic feature for a lake of this kind. (Wikipedia)
Camping in the Limestone Coast
Location from OpenStreetMap contributors (ODbL).