Mérantaise (ruissseau) - Affluent de l'Yvette walks

A hike which is mostly in the forest, with lovely sections along the Mérantaise river and the ditches which run down from the Saclay Plateau.

A loop in the Chevreuse Valley, with magnificent landscapes, in a wooded and rural setting close to Paris. The first part is a walk through the woods on the plateau overlooking the Yvette Valley. The return journey, parallel to the outward route, is mainly on flat ground. Most of the walk is well shaded and flat, but there are also some fairly steep ascents and descents. The area is very popular with walkers and mountain bikers, but it is well worth a visit.

A short hike to discover the Mérantaise valley, the Croix du Bois, the Mérantais wash house, the village of Magny-les-Hameaux, the Maison des Bonheurs (family of 19th-century painters), the Domaine de Brouëssy, and the stele of Hélène Boucher (early 20th-century aviator).

A short walk between forest and fields without leaving Saint-Quentin-en-Yvelines. It will take you to the "Garde Manger", a shop selling local and short route products.

A hike from station to station, yo-yoing between the Yvette valley and the Saclay plateau, with a few fairly steep hills. After a mostly wooded route with some elevation, you cross Gif-sur-Yvette and then walk along a wetland area framed by two rivers. You climb back up onto the plateau, near the Paris-Saclay University campus. After visiting the old Troche quarry and walking along the edge of the plateau, you descend back into the valley.

A circular route that starts on a cultivated plateau before descending into the Mérantaise valley. Then, mostly in the undergrowth, you play leapfrog with the river.

A south-north crossing offering a very varied route. Sections through the forest alternate with stretches across fields. Water features are plentiful, with several rivers—the Yvette, the Marette and the Bièvre—and the Étangs de Montbrond set in their lush green surroundings. (Warning) The route is cut off at the point (12) due to works on Metro Line 18 (as of March 2026). A diversion is under consideration. Please refrain from undertaking this hike until further notice.

This hike starts in Gif-sur-Yvette and takes you to the heights of the Saint-Aubin and Vallée Bonnard channels, following the Yvette river and returning via La Mérantaise, passing through the Bois d'Aigrefoin, the Saint-Aubin communal forest and the Coupières basin.