From the Perdsley the visitor looks at a height of about 400 meters above sea level in the direction of Monschau in the picturesque Rur valley. The name is made up of the terms "Perd" for horse and "Ley" for rock. This designation indicates the earlier use of this place. Up until the beginning of the 20th century, dead horses and other cattle were said to have been thrown down the 75 meter high rock to get rid of the carcasses. Down in the Rur valley these were then either "disposed of" by the fish in the Rur or by the animals living in the valley, such as wild boars, foxes and crows. Since the slopes of the Rur valley in this region are very steep, with some steeply sloping rocky areas, they could not be used for agriculture. The animals and plants living here remained relatively undisturbed and many rare and protected species have been preserved. Above all, there are still animals that rely on high water quality and this special form of the shore zones, such as the kingfisher and the dipper.