A cirque is a bowl-shaped depression found in mountainous regions, formed by glacial erosion. It typically has steep sides and a flat bottom, often containing a small lake called a tarn. Cirques are created when glaciers carve out the landscape as they move, leaving behind distinct features. These formations are commonly associated with the Alps, Rocky Mountains, and other major mountain ranges. Cirques can serve as the starting point for glaciers, which may flow down into valleys, further shaping the terrain. They are important indicators of past glacial activity and help scientists understand climate change over time.