Pilier de Flandenne (Flandenne's Pillar) is located on the cliff above the confluence of Chaillard and Léoncel Rivers near the village of Saint-Martin-le-Colonel on Vercors Regional Natural Park in Drôme department of France. The opening has a measured height of about 18 meters. IGN topographic map Top 25 issue 3136 ET Combe-Laval