Country:
District:
Starting point and access: Courcelle-sur-Yvette station.
- RER - Line B, on the section between Paris and Saint-Rémy-Lès-Chevreuse.
Take Exit 2, Rue Fernand Léger, on the platform heading from Saint-Rémy-les-Chevreuse to Paris (if arriving from the opposite direction, use the underpass).
Yellow markings
(S) On leaving the station, follow Rue Fernand Léger towards the town centre. Pass Allée du Manoir on the left and come out onto a wider road, which is in fact still Rue Fernand Léger. Follow this road to the left and immediately ignore a road on the right.
(1) Cross the Yvette and continue straight ahead. At the end, cross the main road (Rue de Paris on the left, Avenue du Général Leclerc on the right) and take Ruelle d’Aigrefoin (a cul-de-sac) opposite, set back to the right. At the end of the tarmac, go through a forest gate and enter the Aigrefoin Communal Forest. At the fork immediately ahead, climb the steps on the right. Continue along a path that winds upwards and leads to a crossroads (bench).
Signposts for the Gif-sur-Yvette trails
(2) Then take the first path on the right, towards Les Quinconces. Pass under some power lines and continue through the forest. Go straight on, ignoring two successive turnings to the left and then a path leading down to the right.
(3) Then turn left towards Les Quinconces. Ignore a bridle path on the right (not shown on the map) and arrive at a crossroads (elevation 149). Then turn right towards Les Quinconces and descend slightly.
Blue + Yellow markings + directional signposts for the Gif-sur-Yvette trails
(4) At the junction, turn left towards Magny-les-Hameaux.
Blue markings + signposts for the Gif-sur-Yvette trails
At the junction shortly afterwards, continue straight on towards the Marais Bonnard.
(5) At a fork, take the path on the right and descend steeply. At the bottom, at a T-junction, turn left. Further on, at a fork, veer left, cross a stream and arrive at a crossroads.
Blue markings
(6) Turn right towards Marais Bonnard and head downhill. Pass through a forest gate and cross a small car park. Cross the D95 with care and follow the path opposite, slightly to the right, between a horse pasture on the left and a hedge on the right.
(7) Cross a branch of the Mérantaise via a first footbridge. Ignore a second footbridge on the right and follow another branch of the Mérantaise on your right. Cross the river via a third footbridge, then a tributary via a fourth. Now follow the Mérantaise on your left. Come out onto a small road and follow it to the right.
Blue + Red and Yellow markings
(8) At a signpost, continue along the road towards Villiers-le-Bâcle. At the fork immediately ahead, turn left and head uphill along Rue du Fond Guérin. Note the Château de la Grande Barrerie on the left, visible through the branches.
No markings
(9) When you reach a white house covered in vegetation, stay on the road (the marked path on the left is closed until further notice).
Blue + Red and Yellow markings
At the T-junction, turn right onto Allée du Canal. Pass through a forest gate, immediately ignore a path branching off to the left and continue uphill. At the top, pass through a second forest gate, turn left and reach the entrance to the Saint-Aubin forest cemetery. Continue for a few more metres until you reach a small bridge.
(10) Then turn left onto a hard-packed track (do not take the bridge) and follow a ditch on your right. Ignore two successive footbridges on the right. Further on, at the entrance to Saint-Aubin, follow a small road to the left for about a hundred metres.
Red and yellow markings
(11) Turn right towards Saclay and take a footbridge. On the other side, follow a road to the left for a few dozen metres. Then turn right to cross the road carefully and take the field path opposite (blue double-sided sign).
(12) At the end, cross the D36 with care (construction work on both sides for the future Metro Line 18). Continue straight ahead, north-north-east.
Red and yellow + yellowmarkings
(13) At the junction, turn left onto a small road. Pass in front of the beautiful Orsigny farmhouse and continue along a track. Shortly afterwards, at the foot of a telephone pole, take a grassy path on the right. The path gives way to a trail, first running alongside a field on the right-hand side and then between two fenced-off meadows.
Red and yellow markings
(14) At the next three-way junction, follow a track to the left and head downhill. Walk alongside a property wall on your right and stay on the track. Note some lovely houses on the right. At a three-way junction, take the left-hand path, which is shaded.
(15) At the edge of the field, turn right, go through a metal gate, enter a wood and head downhill. At the bottom, go to the left of a fence and follow a first pond on your left. At a fork, veer left to stay as close as possible to the pond.
(16) At the end, turn left and pass between two ponds (path overgrown with vegetation in May 2025). At the T-junction, turn right and follow the second pond on your right. At the next junction, continue straight on and follow a third pond on your right. Cross a stream via a footbridge without a railing and turn left onto a path running alongside the stream.
(17) At the end, take a sharp right-hand bend. Go straight on and ignore a few tracks on the left. After about 400 m, take a sharp left-hand bend and climb gently. Further on, turn right, pass a hairpin bend and come out onto a path at the edge of a field.
(18) Follow the path to the right and immediately ignore a turn-off to the right. Walk between a field on the left and a wood on the right, then along the edge of a wood on the left.
No signposting
Pass through a forest gate, continue straight ahead along a road and pass a riding school on the right.
(19) At the end of the street, turn right. At the corner of No. 6, turn left onto a path between two fences. Then cross a small car park, turn right and go under a porch. Come out onto a street and follow it to the left. Go straight on and ignore the side streets and paths on either side.
(20) At the junction (church on the right), follow the D120 straight on towards Petit Jouy and head downhill (stick to the right-hand pavement). At the Stop sign, go straight on, still on the right-hand pavement, and walk alongside a fenced-off field on your right.
Red and yellow markings
When you reach a forest house, continue straight ahead.
(21) When you reach a bridge over the Bièvre, turn left to cross the road at the pedestrian crossing. Take the hard-packed track opposite towards Buc and follow the river on your left.
No markings
At the end of the track, turn right. Carefully cross the road at the pedestrian crossing on the left. On the other side, go through a forest gate and you will immediately reach a crossroads.
Red and white markings
(22) Take the path on the left (ignore the sign inviting you to continue straight on along the Route des Noyers). Shortly afterwards, turn right onto a stony path and head uphill. At a crossroads (elevation 147), go straight on.
(23) At the next junction, take a path immediately on the left (do not follow the more obvious, compacted track). Wind your way through the undergrowth. At a junction, go straight ahead and continue winding your way through. Ignore a path leading down to the left. At the junction that appears shortly afterwards, turn right and you will soon reach another junction.
(24) Follow the Route du Sud to the left towards Versailles-Chantiers station. Turn right onto the track and walk north-east for about 400 m.
(25) Then take the first path on the left (be careful to spot this turn-off). Descend slightly and, at the bottom, turn right and walk along a wall on your left and past the buildings beyond. At a three-way junction at the corner of the wall, turn right. At the three-way junction that appears shortly afterwards, turn left. You will come out onto a road; follow it to the left.
(26) At the traffic lights, cross the D938 at the pedestrian crossing and follow it to the right. Go under the motorway bridge and, on the other side, turn left onto a gravel path (forest gate). At the first junction, go straight on. At the second junction, turn left. At the next junction, turn left.
(27) At a crossroads, go down a flight of steps on the right. At the bottom, follow a road to the left and downhill. At the end, cross a cobbled street and climb a flight of steps. Then turn right and cross the railway tracks. Continue along Rue Édouard Charton. Take the first right, a cul-de-sac, into Passage des Étangs Gobert. Go through a gate then turn left to climb two successive flights of steps.
(28) At the top, follow a gravel path straight ahead. Cross a road and walk alongside the Jardin des Étangs Gobert on your left. Shortly afterwards, turn sharply right towards the station and walk downhill. At the bottom, first turn right then left to take the Passage des Jardins. At the end, turn right to find the escalators leading to Versailles-Chantiers station (E).
To get back home:
- RER - Line C, towards Paris (then Dourdan or Étampes) or Saint-Quentin-en-Yvelines.
- Transilien -
. Line N, towards Paris-Montparnasse, Rambouillet, Dreux or Mantes-la-Jolie.
. Line U, towards La Défense or La Verrière.
. Line V, towards Massy-Palaiseau.
Visorando member
Moderate 
Easy 
