From Palaiseau to Le Guichet via Vauhallan Abbey

Starting point and access: Palaiseau station.
- RER - Line B, on the section between Paris and Saint-Rémy-lès-Chevreuse.
Take Exit 2, Boulevard Bara, at the front of the train when travelling from Saint-Rémy-lès-Chevreuse to Paris (if arriving from the opposite direction, take the footbridge at the rear of the train).

No signposting

(S) On leaving the station, cross Boulevard Bara and head uphill along Rue du Mont. Pass Rue Jeanne d'Arc on the right; note a small patch of vines on the right and climb a flight of steps. At the top, continue straight ahead along a street, still going uphill.

(1) At the traffic lights, cross a wide street then turn right into Rue Louise Bruneau. At a fork in the road, follow the Chemin de Vauhallan to the left. Cross Rue Gabriel Dauphin on the left and continue straight ahead along the street, which is a dead end. Walk past allotments on your left, then a sports complex.

Red and yellow markings

(2) Cross the road carefully at the pedestrian crossing (speed bumps). Then take a footbridge over a three-lane road.

(3) On the other side, turn left and follow a well-maintained track towards Saclay (shared path for pedestrians and cyclists). Turn right onto this track (old coat-of-arms marker) and follow a drainage channel on your right.

(4) Carefully cross a small road at the pedestrian crossing (forest barriers). Continue along the hard-packed track between the fields and alongside a ditch.

Red and white + red and yellow + yellow markings

(5) At the junction, turn right, cross the bridge over the ditch and follow a small road. After about a hundred metres, ignore a path on the left (this will be the return route), continue along the road and pass the Ferme de Villebois.

Yellow markings

(6) At the next junction, stay on the road and follow the^PR® des rigoles du plateau (let the^GR® head off to the left). Shortly afterwards, as you come out of a right-hand bend, leave the road, turn right onto a wide, hard-packed track and follow a horse pasture on your left.

(7) After a right-hand bend, turn left onto a faint path. Immediately ignore a path branching off to the left and head down alongside a stream on your right (wet sections). At the bottom, ignore a path branching off to the left and cross the stream. Now follow the stream on your left. Cross the stream again, ignore a path branching off to the left and arrive at a T-junction by the houses.

(8) Turn left and immediately reach a street. Then take a path on the left and climb slightly. At the next junction, turn right. Cross a small road, continue along the path opposite and immediately ignore a turn-off on the left. Descend to a road. Follow this to the left and, after about 50 metres, take a path on the right (zigzag).

(9) After about 100 metres, there are two options:
- Turn left onto a boardwalk (unmarked; shaded section; take care of slippery conditions after rain). At the end, cross a river via a footbridge and rejoin the main route at (10).
- As shown on the map, turn right onto the path. Further on, turn left and walk along a large lawn on your left.

(10) At the fork in the road, turn right (left if coming from the boardwalk). You’ll reach a small car park. Cross it diagonally to the left and take a slightly downhill, well-maintained track. Cross a river via a footbridge and climb gently up the other side. Turn right along the path and pass between some houses.

Red and white + red and yellow markings

(11) At the end (with a wash house on the right), follow the Chemin du Limon to the left and uphill. Further on, pass through a forest gate and climb a path interspersed with steps. You’ll come out onto a small road; follow it to the right.

(12) At the corner of a building, turn right. Note a dovecote on the left in the middle of a vineyard plot and pass in front of the entrance to Vauhallan Abbey. At a Fork in the road, keep left. Then take the first path on the left (pétanque court). Pass through a forest gate and head downhill along a path.

Yellow markings

(13) At the bottom (wetland), follow the^PR® des rigoles du plateau to the right (let the^GR® head off to the left).

No markings

After about a hundred metres, take the first path on the left. At a three-way junction, veer left and walk along a wasteland on your left. You’ll come to a small road you took earlier; follow it to the right and cross the bridge over the ditch.

(5) Continue straight on along the small road towards Orsay. At the traffic lights, cross the D36 using the pedestrian crossing on the right-hand side. Enter Palaiseau and continue along a tarmac path running parallel to Avenue de la Vauve. Ignore the entrance to a waste collection centre on the right.

(14) Shortly afterwards, turn right onto a wide, compacted track. Walk along the left-hand side of a retention basin (information boards). Then take the first narrower path on the left. At the end, cross a road and follow Rue Rosalind Franklin opposite. Walk along the right-hand side of the EDF research centre. At the traffic lights, cross Boulevard Monge in two stages and pass under the elevated metro viaduct (station on the left).

(15) Then follow the boulevard to the right. Take the first left, Rue André Hardy. Walk past the Campus Agro Paris-Saclay on your right. Cross Cours Pierre Vasseur on the right-hand side and continue straight ahead. Cross a boulevard and continue straight ahead on a wooden walkway (caution: there are holes and the surface may be slippery after rain). At the end, turn left and you will immediately see a staircase on the right.

(16) Go down the steps then take a footbridge (the former La Troche sandstone quarry lies below on the right). Continue through the woodland on a concrete path. At the end, cross Rue de Corbeville and follow Rue de la Vauve straight ahead (signposted further on). At the junction, go straight on. At the end of the street, go down a steep flight of steps. At the bottom, cross a street and go down another, less steep flight of steps, the Passage du Buisson. At the bottom, cross a street at the pedestrian crossing and continue straight ahead into Rue du Pont de Pierre. You will soon reach Guichet station (E).

To get back home:
- RER - Line B, towards Paris (do not take the bridge; turn right then go down the stairs on the left leading to the platform) or Saint-Rémy-lès-Chevreuse (take the bridge over the railway line and you will find the access to the platform immediately on the right).

In dry weather, good trainers are sufficient. Hiking boots are useful in wet weather: potentially muddy sections between (7) and (9) and between (13) and (5).

No water points identified along the route. Bar-restaurant on the corner of Cours Pierre Levasseur, between (15) and (16) (open weekdays only).

A detailed map is useful (at the very least the one accompanying this description).

Walk completed by the author on 1 February 2025.

- Drainage channels on the Sacaly plateau, between (3) and (5). These channels were constructed to supply water to the park of the Palace of Versailles.
- The pleasant Parc des Sablons, between (9) and (10).
- Vauhallan Abbey (12).
- The modern architecture of the university campus, between (14) and (16).