FR-293. This natural tunnel is located above Lac de Peiroou (Peiroou Lake) near the village of Saint-Rémy-de-Provence on Bouches-du-Rhône department of France. On the difficult section of the passage inside the tunnel, some fasten rung and a hand rail makes an easy climb to the other side. Note the person below for scale. The well signed long distance GR 6 crosses the natural tunnel. IGN topographic map Top 25 number 3043 west Saint-Martin-de-Crau (pleat A2).