Glendalough is situated at about 40 kilometers south of Dublin and is well known because of its monastic ruins. This monastery was founded by Saint Kevin in the sixth century A.D.. From a geographic viewpoint, Glendalough is interesting as well. In the picture it is clearly visible that the monastery is located in a U-shaped valley. These U-shaped valleys are created by glaciers. Rivers, on the other hand, usually create V-shaped valleys. Because the base of a glacier is more or less flat, glaciers create U-shaped valleys.

Though, the presence of a U-shaped valley is an evidence that once a glacier was located here.