Mount Gambier is a city in the Limestone Coast region of South Australia. It is the second most populous city in the state, with a population of over 28,000 people. The city is located on the slopes of Mount Gambier, an extinct volcano, and is known for its natural beauty and unique geological features. The city is home to a number of attractions, including the Blue Lake, Umpherston Sinkhole, and the Cave Gardens. It is also a popular destination for outdoor activities such as fishing, camping, and hiking.