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, collecting snow and ice over time. These geological features are commonly associated with the Alps, Rocky Mountains, and other high-altitude areas. Cirques can serve as the starting points for glaciers, which may flow down into valleys, further shaping the terrain. They are important indicators of past glacial activity and climate change.