After the Col de la Machine, the road, which is carved into the extraordinary limestone rock face, begins to curve vertiginously over the upper valley of Cholet, which you ultimately tower over from a height of 600m. At the far end of the cirque is the Cascade du Cholet, which surges out of the Brudour cave. After passing through several tunnels the road comes out over Royans: here you have marvellous views over the hilly landscape as well as the Plateaux du Bas Dauphiné (Chambaran Forest).