Avoid leaving the paths and keep your dog on a leash from April to July.
40m after Le Smile, in the sector Arcades. Jumpstart to a big horizontal gully, climb the overhang with the feet in the gully and exit above.
From the parking lot of La ferme du Montrouget, pass the main sector, take Le Chemin de la Roche qui Tourne (GR) for 40m to the East and follow a small path up the slope to the South for 150m. The boulder is at the end of the valley, 40m to the North after Le Smile.