Athletic wall on the left of the boulder of "Le Phalloïde" (big boulder on the top of the hill, 200m to the North-East of Alien). Standing start in the middle of the wall and exit via the arete.
Follow Le Chemin de la Pente de la Garenne and turn left at a characteristic table of the "sentier de découverte". The boulder is near the top of the slope on the left side of the thalweg.