Answer: Cirque
Explanation: Cirques are bowl shaped, circular depression that are formed at the top region of the mountains, due to the melting and erosion of glaciers. It is an erosional feature.
Cirques are separated from one another by aretes, that are steep narrow long ridges found at the top part of the mountain. The walls of this cirques are very steep and their diameter ranges upto a size of 1 kilometer.