Mount Gambier is the second most populous city in South Australia with a population of 25,199 in the urban area, or 27,756 if associated peri-urban communities are included (2011 Census). The city is located on the slopes of Mount Gambier (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, it 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.