Mount Gambier (volcano) in the context of Newer Volcanics Province

Mount Gambier is the second most populated city in South Australia, with a population of 25,591 as of the 2021 census. The city is located on the slopes of Mount Gambier, a volcano in the south east of the state, about 450 kilometres (280 mi) south-east of the capital Adelaide and just 17 kilometres (11 mi) from the Victorian border. The traditional owners of the area are the Bungandidj (or Buandik) people. Mount Gambier is the most important settlement in the Limestone Coast region and the seat of government for both the City of Mount Gambier and the District Council of Grant.

The city is well known for its geographical features, particularly its volcanic and limestone features, most notably Blue Lake/Waawor/Warwar, and its parks, gardens, caves and sinkholes.

Blue Lake / Warwar (The Blue Lake) is a large, monomictic, crater lake located in a dormant volcanic maar associated with the Mount Gambier maar complex. The lake is situated near Mount Gambier in the Limestone Coast region of South Australia, and is one of four volcanic crater lakes originally on Mount Gambier maar. Of the four lakes, only two remain, the other one being Valley Lake / Ketla Malpi; the other two, Leg of Mutton Lake / Yatton Loo and Brownes Lake / Kroweratwari, dried up as the water table dropped.