Country:
District:
Starting point and access: Palaiseau station.
- RER - Line B, on the section between Paris and Saint-Rémy-lès-Chevreuse.
Take exit 1, Rue de la Gare, at the rear of the train when travelling from Paris to Saint-Rémy-lès-Chevreuse (if travelling in the opposite direction, take the footbridge at the front of the train).
Yellow + Green signage
(S) When you leave the station, walk a few metres along Rue de la Gare and climb the stairs immediately on your right. Then first turn left then right to take Rue Alexandre Néreau. Walk along this quiet street, which winds its way between beautiful houses. At number 44, turn left onto a path (chicane) and go downhill.
Yellow markings
At the bottom, cross Rue de Paris and go around the town hall on the right (note the mural on the right inspired by the French Revolution). At the corner of the town hall, turn left. Then take a paved path on the right and go straight down through a public park. Go down a staircase and then turn left until you reach a roundabout.
Go around the roundabout on the right and take thefirst exit, Rue Victor Hugo, towards Champlan. Take thefirst left, Sente des Rieux. At the crossroads, go straight ahead (private residence with pedestrian access). At the end of the tarmac road, continue along a path. When you reach a small car park, go down the steps on the right and then turn left to go around a boules court on the left. Walk along a football pitch on your right, go through a gate and you will come out onto a street.
No markings
(1) Turn left to cross the street at the pedestrian crossing and pass under the A10 motorway bridge and then under the TGV bridge. Immediately turn right onto Rue Cyprien Muret. At the end, turn right and pass under the railway bridge and motorway bridge again. Walk along the Yvette on your left, cross a perpendicular stream and turn left to stay as close as possible to the river.
(2) At the corner of a car park, take a footbridge over the Yvette. Continue straight ahead along the sports facilities. At the end, cross a footbridge over a secondary branch of the Yvette (the Boële).
Yellow markings
At the end of the footbridge, take a gravel path on the right (the Promenade de l'Yvette). Follow this path as close to the river as possible and ignore all turnings on the left. At a small dam (where the two branches of the river meet), turn left and climb slightly to a roundabout (do not take the small pedestrian tunnel).
No markings
(3) Turn right, cross the bridge over the Yvette and leave Villebon via a street that curves to the right. Ignore Allée Roger Collet on the left.
Red and yellow markings
Immediately afterwards, turn left and go up Rue Lazare Hoche (not signposted here). After No. 21, turn right into Rue Amable Tastu. Follow this path between walls and garden fences.
No markings
At the end, turn left (leaving theGRP® trail on your right). At the traffic lights, go straight ahead onto Rue Blaise Pascal. At the end, follow Rue de Paris on your right. Take thefirst left onto Rue Camille Desmoulins. At the fork immediately ahead, turn right onto Rue Thomson and go uphill. At the end, turn left. At the next crossroads, turn right and go under the railway bridge (there is only one pavement, on the left-hand side). Cross Chemin de la Savetière on the right-hand side and you will come to a crossroads at the corner of the Palaiseau cemetery. Turn right into Rue du 11 Novembre 1918 and walk along the cemetery on your left.
Red and yellow + yellow markings
(4) At the corner of the cemetery, turn left 90° onto a cement path and rejoin the GRP®. After the cemetery, continue along a dirt track and climb a very steep hill. After a flat section, continue climbing, less steeply, along property fences. Finally, climb a staircase and come out onto a street. Then turn left then right to cross the street and walk along a white house on your right. Then turn right twice to take a paved path for pedestrians and cyclists.
Red and yellow markings
(5) When the track turns right, turn left onto a gravel path and enter the Palaiseau National Forest. At a triple fork, take the middle path, which is the narrowest. Ignore the path coming from the right. At the next junction, turn right, ignore a path on the left and continue straight ahead (north). Cross a tarmac lane, continue straight ahead and ignore two paths on the left.
Red and white markings
(6) At the next junction, follow theGR®655to the left (leaving theGRP® to the right).
No markings
At the T-junction, turn right (leaving theGR® trail to the left). At the next junction, turn left and pass a bench on the left-hand side. Walk along a wide, stabilised lane, which initially heads west and then curves south, ignoring all the narrower paths on either side. You will reach a junction with a wide tarmac lane at the foot of a radar tower on the right, beyond a wire fence.
(7) Follow the tarmac lane to the left for about 250 m.
Red and white markings
Rejoin theGR® at a junction with a path and follow it to the right. Follow the main marked path and ignore several paths branching off to the sides. Cross a stream and, at the three-way junction that follows, take thesecond path on the right. At the next three-way junction, turn left at the edge of the forest. When you reach a road, turn left again to cross the road at the pedestrian crossing.
Red and white + yellow markings
(8) Turn right onto Chemin de la Hunière et des Joncherettes. Stay on this tarmac path, which is reserved for pedestrians and cyclists, and ignore any side paths.
Yellow markings
After about 800 m, at a fork, continue straight ahead on flat ground to follow the circular forest trail (let theGR® trail descend to the left).
Blue + pink markings (+ a few oldGR® andPR® markings)
(9) Cross a cement path and continue straight ahead on the circular forest path. Stay on the dirt path through the woods and ignore any vague tracks on the sides. At a fork (not shown on the map), turn right and head towards the edge of the forest and the edge of the plateau and Saclay campus. The dirt track gives way to a path covered with railway ballast-type stones. Come out onto a small road and follow it to the right for a few metres until you reach a crossroads.
Yellow + Blue markings
(10) Ignore thefirst left, which leads to the old Vauve farm (information sign), and take thesecond left, a paved dead-end road. At the next intersection, go straight ahead.
Blue markings
At the information sign and just before a footbridge on the right-hand side, turn left onto a dirt track leading downhill.
Yellow + blue markings
At the T-junction at the bottom, turn right. Reach the old Troche sandstone quarry (now a climbing school) and walk along it on your right.
(11) At the end of the quarry (information sign), turn left. Climb a wooden staircase and you will come to a street (Rue de Corbeville on the map).
No markings
Follow the street to the left and immediately ignore a street on the right. Take the next right, Rue de la Vauve. At the crossroads, continue straight ahead.
Blue markings
At the next crossroads, go down the large staircase opposite.
Yellow markings
At the bottom, take thesecond street on the left, a downhill street with a speed limit of 20 km/h. At the next intersection, continue straight ahead on Rue de Châteaufort and go uphill. Cross Passage du Rocher on the left and turn right with the street. Almost at the end of the bend, turn left and go up Sentier de Châteaufort (a cemented dead-end road). At No. 11, turn right.
(12) Just before No. 17, go down two steps on the right and take a path between two fences (be careful to spot this start). Turn left onto the path and continue on flat ground. Shortly before the path goes uphill, turn right between two property fences and go downhill. Turn left along the path and continue between walls and property fences. Come out onto a street and follow it downhill to the right. At the traffic lights, turn left and, at the next traffic lights, left again. Walk along the railway line on your right and continue straight ahead to Lozère station (E).
To return home:
RER - Line B, towards Paris (direct access) or Saint-Rémy-lès-Chevreuse (take the underground passage).
Visorando member
Easy 
Difficult 
Association / Club / Walk leader
Very difficult 
