Derborence. A virgin forest grew on the rock debris. It consists of spruce, pine, larch, stone pine, beech and willows. The area was acquired by Pro Natura in 1961 and is now protected.
The valley, which is exceptionally rich in fauna, is a natural habitat for ibex, chamois, deer, marmots and hares and several bird species including the owl, golden eagle, bearded vulture and alpine chough.