Vaux de Cernay, human settlement in France

Vaux de Cernay is a narrow, marshy-bottomed valley in the Haute Vallée de Chevreuse regional park, where the ru des Vaux forms small cascades called the "bouillons de Cernay" over large sandstone blocks. The wooded, rocky slopes are crossed by marked paths and a branch of the GR 1, and the D 24 winds through. The most visited stretch, about five kilometres long, holds the ponds and ruins of the Cistercian abbey.

Artaud, sent by Saint Godefroy of Savigny, installed about twelve monks in the marshy Bric-Essart valley on 17 September 1118, after a gift from Simon III de Neauphle-le-Château and his wife Ève. Built first in wood, the abbey was rebuilt in stone from 1145 following drainage works around the ru des Vaux. Its attachment to Cîteaux in 1147 made it a Cistercian abbey in the line of Clairvaux. Commendation in 1542 brought ruin, and the community was dissolved in 1791.

Painters of the Cernay school worked outdoors in the valley in the second half of the 19th century, lodging at inns such as "Chez Léopold" and "Au Rendez-vous des Artistes" in Auffargis and Cernay-la-Ville. Their leader, Léon Germain Pelouse, has a monument by the sculptor Falguière near the Cernay pond dam. The ru des Vaux still feeds the ponds and the water features of the Dampierre château park.

The site is accessible from multiple parking areas, with walking trails ranging from four to eighteen kilometers passing through woods, fields, and valleys. Guided walks are available year-round and typically last from a few hours to half a day, offering deeper insights into the landscape and local history.

The abbey's church hosted the tomb of Thibaut de Marly, abbot from 1235 and canonised in 1270; Philip the Bold, Philip the Fair and Charles VI came to kneel there. Victor Hugo visited and drew the rose window of the abbey. The community was dissolved in 1791 and its furnishings sold off by order of the Dourdan tribunal.