An arête ( ə-RET) is a narrow ridge of rock that separates two valleys. It is typically formed when two glaciers erode parallel U-shaped valleys. Arêtes can also form when two glacial cirques erode headwards towards one another, although frequently this results in a saddle-shaped pass, called a col. The edge is then sharpened by freeze-thaw weathering, and the slope on either side of the arête steepened through mass wasting events and the erosion of exposed, unstable rock. The word arête (French: [aʁɛt]) is actually French for "edge" or "ridge"; similar features in the Alps are often described with the German equivalent term Grat.
Where three or more cirques meet, a pyramidal peak is created.
