The Hauts-Plateaux nature reserve ranges in altitude from 1 200m to 2 300m. It is made up of limestone plateaux whose surface is punctuated by limestone pavements and grottoes where water is scarce. Its border is marked by extraordinarily steep slopes that look over Gresse to the east and La Chapelle-en-Vercors to the west. The reserve also encompasses the two highest peaks of the Vercors: the Grand Veymont (2 341m) and the emblematic Mt Aiguille (2 086m). The area is home to black grouse, mountain hares, huge numbers of chamois, Alpine ibex and, only recently, Griffon vultures.