Voisins-le-Bretonneux is part of Saint-Quentin-en-Yvelines, one of the new towns built around Paris from the 1970s onwards, and on first sight it is all office parks, roundabouts and housing estates. But it sits right on the edge of something much older and lovelier: the Haute Vallée de Chevreuse, a regional natural park of wooded valleys, streams, villages and châteaux just south of Versailles.
A few minutes away, in Magny-les-Hameaux, lie the remains of the abbey of Port-Royal des Champs, the centre of the Jansenist movement in the seventeenth century. The playwright Racine was educated here, and Pascal had close links with the community. Louis XIV, suspicious of the Jansenists, had the abbey destroyed in the early eighteenth century, but the ruins and the museum in the old buildings are atmospheric. The Vallée de Chevreuse itself, with the castle of La Madeleine above Chevreuse and the gorges of the Vaux de Cernay, is a favourite escape for Parisians.
As a start and fuel stop, Voisins is practical. There are service stations and supermarkets close by, and the roads into the Vallée de Chevreuse start almost immediately. The routes down into the valleys and up onto the plateaux are winding and pleasant, with short climbs, tight bends in the woods and some lovely stretches along the streams. Surfaces are generally good, but expect cyclists in large numbers on weekend mornings, and speed limits are strictly enforced.
Get here early on a Sunday and you will have the valley largely to yourself, with mist in the hollows and the forest smelling of damp leaves.