Park in the car park at the Leclerc in Gometz.
(S/E) Follow the cycle path heading north-east for about 200m (running alongside the bypass, which is in a tunnel).
(1) Take the path on the right which quickly turns south-west (it runs alongside the bypass but heads south). 700m further on, when you reach the road coming from Roussigny, turn right for 50m to go up the small ramp on the left leading to the old Aérotrain track.
(2) Leave this track almost 2 km further on, just before a bridge over a small road; turn left onto an access path leading to the road. Follow this road, which is also theGR®11, marked in red and white. Pass the Bénerie rest stop.
At the small roundabout, take the road straight ahead. Reach the hamlet of Roussigny.
(3) Leave theGR®11here and take the road on the left for 300m, then the path on the right. Join the D131 road.
(4) At the junction, straight ahead (a slight left-right bend), 700 metres further on, a path joins from the right; follow it straight ahead, then, 200 metres further on, take the grassy path on the right.
You’ll arrive at the hamlet of La Brosse.
(5) Take the road straight ahead, then the path that continues from it.
Follow the signposted hiking trail.
Carry on straight ahead at the first path junction, then turn left at the second junction, as indicated by the signposts. You’ll reach theGRP® du Hurepoix junction.
(6) Enter the forest; the path descends gently at first, then a little more steeply. After crossing the stream, the path climbs steeply. You’ll come out onto the road.
(7) Turn left, passing by the small cemetery.
Follow the road which runs past the castle, turns due north; leave the GRP® here.
Head towards the hamlet of Villeziers. Follow the signposts leading to the pedestrian tunnel under the motorway.
(8) When you reach the car park at the Les Ulis shopping centre, turn left.
Head for the exit, turn opposite and walk alongside the secondary school. The road becomes a cycle path; follow it.
(9) At the hamlet of Saint Clair, turn right (Viaduc des Fauvettes) but only for 100m, as you must then turn left onto a winding path. You’ll emerge near a stadium. Turn right for 10 metres, then immediately left across the sports grounds. Join a small road which takes you to the roundabout at the northern end of the Gometz bypass. Take the cycle path towards the tunnel.
(1) Follow the outward route back to the car park (S/E).