Here's how it forms:
* Glacial erosion: As a glacier moves down a mountainside, it erodes the rock and soil, carving out a bowl-shaped depression called a cirque.
* Backwall: The steep, almost vertical wall at the back of the cirque is called the backwall.
* Armchair shape: The cirque's distinctive armchair shape is created by the glacial erosion, with the backwall forming the back of the chair and the sides sloping down to the front.
Cirques are common features in mountainous areas that have been glaciated. They often contain lakes or tarns, which form when the glacier melts and leaves behind a depression filled with water.
