The Upper Bièvre Valley is a territory made up of eleven municipalities within the departments of Yvelines and Essonne. This site was classified on 07/07/2000 along the river Bièvre, which has its source in Guyancourt and flows into the Seine in Paris.
This natural area is rich in heritage and has the advantage of being close to Versailles and Paris. The municipalities crossed by the Upper Bièvre Valley are : Guyancourt, Buc, Les Loges-en-Josas, Jouy-en-Josas, Vélizy-Villacoublay, Bièvres, Saclay, Vauhallan, Igny, Massy and Verrières-le-Buisson.