Country:
District:
Start
The hike starts at Palaiseau-Villebon station (RER line B).
(S/E) Leave the station via the exit on the Boulevard Nicolas Samson side. Cross the roundabout and go down Rue Lazare Hoche until you reach Rue George Sand, which you take on the right to reach the bridge over the Yvette.
PR® signposts (yellow)
(1) At the end of the bridge, turn left onto the Promenade de l'Yvette, which follows the right bank of the Yvette for a few metres, then the right bank of one of its branches (the Boële). Continue through a tunnel under the A10 motorway and the TGV Atlantique railway lines. At the end of the tunnel, the promenade changes banks until you reach a bridge, which you cross to return to the right bank of the Boële and join a road.
(2) Cross the road and continue along the walkway on the left bank of the Boële until it joins the Yvette, which you cross via a bridge to reach a road a few metres further on.
(3) Cross the road. Pass in front of the entrance to the Boule Salucéenne club grounds. Follow the left bank of the Yvette, cross the first bridge on the right. Continue along a paved path, with the lake on your left. Leave the path and cross the Yvette on another bridge (Pont de la Planche aux Vaches). Continue along a path that leads to a road in front of a car repair shop.
(4) Cross the road and go through the green turnstile to the left of the garage (temporarily leave the yellow markings). Take the boardwalk to cross a marshy area. Then rejoin the markings and follow a path that climbs up to a crossroads in the village of Saulx-les-Chartreux.
(5) Cross the crossroads (which is offset to the left), continue along Rue Jean Antoine Léonardi and turn left at the corner of the cemetery to follow it. At the next corner, turn right. Walk along a park until you reach Rue Léon Chartier, which you take on the left. After about 50 metres, turn right into Rue de la Gare.
(6) This street becomes a farm track as it leaves the built-up area. Cross an area of market gardens. Continue, curving south-southeast, ignoring the few junctions with other tracks, until you reach a road with a pedestrian crossing.
(7) Cross and turn right. Two hundred metres later, cross the junction and follow the path uphill into the forest. This path ends on a road in front of a property at No. 15.
GRP® Green Belt of the Ile de France (Red and Yellow)
(8) Turn right and two hundred metres further on, when the road turns left, continue straight ahead into the forest. A little further on, at the corner of plot 26, theGRP® turns left. Leave the markings for a moment and continue straight ahead along the forest track, which is less muddy than theGRP® in wet weather (you will find the signs again after 500 metres). Walk along plots 14, 13 and then 29 (where theGRP® signs are visible again) and you will reach a crossroads between plots 10, 12, 29 and 31.
(9) Turn right between plots 10 and 12 onto the path that descends to the viewpoint protected by a metal railing. Then turn around to return to the crossroads and turn right to follow the track separating plots 10 and 31.
Turn left between plots 31 and 34 at the next fork. The path ends at a wide track closed off on the left by a row of large boulders. Turn right and, 200 metres further on, turn left onto the path crossing plot 5. This leads to a road.
(10) Cross the road and continue straight ahead. Pass a car repair shop and then a horse riding centre. At the crossroads, continue straight ahead along Chemin des Galennes until you reach Chemin de la Fontaine de Fer, where you turn left. Cross the plain and, at the corner of a large fence, turn left.
PR® signposting (yellow)
(11) Follow the wall and enter the hamlet via a narrow passage ending at Rue de Saulx-les-Chartreux. Turn left, then left again at the crossroads into Rue Emile Chartier. At the crossroads, go straight ahead into Chemin des Hauts des Paradis. The road climbs steeply and ends in a staircase leading to a street about 100 metres from the traffic lights.
(12) Turn right and, at the traffic lights, right again into Rue du Bois Courtain, which continues straight ahead into Chemin des Casseaux. Cross the road and continue straight ahead. The road curves to the left and overlooks the A10 motorway. When you reach a recent interchange, turn right to cross the bridge over the motorway. Go around the radio relay enclosure on the left.
(13) Turn right at the crossroads to descend into the valley. When you reach the street, turn left onto the path, then turn right 200 metres later onto the steeply sloping path leading to Rue Muller at the entrance to a bridge.
At the end of the bridge, continue along Rue Le Perdriel, which winds its way to Rue des Casseaux. Turn left and then right after about 100 metres onto the Trou Rouge path, which descends to the Yvette promenade.
PR® signposting (yellow) (there is also red and yellowGRP® signposting)
(14) Turn right and follow the Promenade de l'Yvette until you reach Rue du Moulin de la Planche.
No markings
(15) Cross the bridge on the left, then turn right onto Rue Léon Bourgeois, which climbs up to Rue Lazare Hoche. Then turn left to reach the RER station in front of you (S/E).
Association / Club / Walk leader
Very difficult 
Difficult 
Visorando member
Easy 
