Aretes
Aretes are also formed by a type of glacial erosion called valley glaciers. Aretes are formed by two cirques on opposite sides of a valley meeting, in which it forms a sharp, steep ridge. The arete that is left separates the two valleys. The edge is sharpened by the freeze-thaw weathering, and the slope on either side of the arete steepened through mass wasting events and the erosion of the exposed, unstable rock.
The Garden Wall in Glacier National Park. This was possibly created by two cirques on opposite sides of a valley meeting in the middle forming a thin and sharp ridge. Another possibility and the typical form of a aretes is when two glaciers erode parallel U-shaped valleys.