From the parking lot along the D64, to the opposite of the road toward La Canche aux Merciers, take a small path for 150m and turn right at Le Chemin du Bois Rond; the starts of the yellow and blue circuits can be found in the slope 100m to 150m after (in front of the start of the red circuit of Le Bois Rond). The problems pricipally opened by Bernard Théret are located along those circuits (see the topo).