Roll out of Choisel and the forêt de Rambouillet opens the ride, before the Château de La Celle appears along the way. Then it's into the Parc naturel régional de la Haute Vallée de Chevreuse, with the Marais du Cerisaie reserve and the étangs et rigoles d'Yveline following in turn. Past the castles of Dampierre and Mauvières, the loop turns for home. All 81.5 km are paved, with 507 m of climbing along the route.
