Following the Orge from Dourdan to Saint-Chéron

Departure from Dourdan station (RER line C, on the section between Paris and Dourdan-la-Forêt). Take the Place Amédée Guénée exit, on the side of platform 1 (Paris-Dourdan direction; if arriving from the other direction, take the underground passage).

No markings
In the town centre, you will occasionally come across the^GRP®® du Hurepoix, which is only mentioned here when necessary.

(S) When leaving the station, take Rue Amédée Guénée opposite, then the first left, Rue Sarcey. At the roundabout, cross Avenue Carnot and take the next street on the right, Rue Émile Renault. At the end, turn left towards the town centre, Rue de Chartres. Pass in front of the war memorial and you will come out in front of the keep of the Château de Dourdan.

(1) Go around the castle on the left and turn right onto Place du Général de Gaulle to reach the castle entrance, near the church. Turn left onto the square and head for the market hall. Then take the first right (red and yellow arrow), Rue de l'Abbé Fèvre. Turn right at Porte de Vie. At the next fork, turn right uphill.

At the crossroads, take the second left (red and yellow sign), Rue des Fossés du Château, a cobbled lane running alongside the castle moat. At the end, go down the steps on the left. At the bottom, continue straight ahead into a street. At the stop sign, go straight ahead onto Rue Basse Foulerie and continue straight ahead at the next stop sign. At the third stop sign, go straight ahead again and cross the Orge river.

(2) Immediately turn left onto Promenade R. Veneau. Immediately afterwards, cross the Orge again and follow the river on your right along a stabilised path (note the old wash houses on the opposite bank). Ignore a footbridge and then a bridge and stay on the path along the river. At the end, follow a street on the left for a few metres.

At the roundabout, turn right onto Rue du Chariot. At the stop sign, cross Avenue d'Étampes and follow it to the right for about 50 metres. Take the first left, Rue Georges Deniau, and you will find the Orge river on your left. Go to the end of the street and, at the roundabout, turn left into Rue de la Gaudrée. The road then climbs slightly.

At the crossroads, take the first left, Rue de l'Ermitage, and then immediately left again onto Chemin de Oysonville, alongside some small buildings. Go through a forest gate and continue along a stony path downhill alongside a wall on the left. Continue straight ahead on a sandy path through the woods with the Orge river below on your left. Ignore a path on the right and then a footbridge on the left and continue along the river. Ignore a path on the right and go straight ahead along a fence on your right.

Red and white markings

(3) Come out onto a street, follow it to the right and cross Rue des Meuniers on the right. At the stop sign, turn right and stay on the right-hand pavement of the avenue until you reach the pedestrian crossing opposite the entrance to a campsite. Cross the avenue and its grassy verge to find a stabilised path below. Follow this path to the right along the avenue. Turn left and enter the woods on Chemin de Malassis. Stay on this main path at the edge of the woods, but inside them, and ignore the paths branching off to the sides.

No markings

(4) At the crossroads, follow the road to the left (let the^GR®®1continue straight ahead). After a hundred metres, leave the road on the left, pass through a forest barrier and take a grassy path along a fence on the left-hand side. Cross the Orge river via a metal footbridge, immediately turn right onto a wide grassy path and walk alongside a pond on your left. After a second forest barrier, turn right onto a gravel path along a wall. At the T-junction, follow the road to the right until you reach the traffic lights at the corner of the church.

Yellow markings

(5) Turn right onto Rue de l'Orge. At the end of the 30km/h zone, follow Chemin des Prés (tarmac) to the left.

No markings

At the stop sign, continue straight ahead on the small road towards Sermaise and pass the old and imposing Moulin Poissard mill. At the fork, take the left road, still towards Sermaise. Pass the sign marking the entrance to the small hamlet of Moraise and continue for a few more metres.

Yellow markings

(6) At the corner of the last house, turn right towards La Bruyère (wooden sign). The tarmac quickly gives way to a grassy path closed to motor vehicles, which starts with a slight incline between two fences. At a fork, take the path on the right, which is wider and less steep. Climb into the woods and, at the next fork, turn left. You will immediately come to a small road. Follow it to the left and cross Chemin de la Garenne on the left.

Red and white markings

(7) At Chemin des Gouttières, rejoin the^GR®®1and continue straight ahead. At the next fork, turn left onto Chemin de la Brière. After crossing Chemin de la Garenne on the left, continue on Chemin de la Brière, which becomes a farm track. At the end, follow a road to the left, pass Ferme de Villeneuve and then walk along a wood on your left.

(8) At the corner of the woods, leave the road and take the second path on the left, the widest one, with a sign bearing the number 208 (the first path, which enters the woods, is not shown on the IGN map). When you reach the gate at number 208, turn right and follow a path downhill between a hedge on your left and a field on your right. At the end of the field, turn left onto a grassy path. Back on the tarmac, ignore the car park on your right and follow the street in the wrong direction. Go around the church on the right (temporarily leaving the^GR®® which goes around it on the left... which offers a less attractive view). Turn left at the war memorial and rejoin the^GR®® at the side of the church.

Red and white + yellow markings

(9) Continue along the street and pass in front of the town hall. At the crossroads, follow the Route de Blancheface opposite towards La Charpenterie. At the corner of No. 34, turn right onto Sente de la Princerie. Initially very narrow between two walls, it widens and climbs into a wood. At the corner of a fence on the right-hand side, continue through the wood and then along the edge of a meadow. At a fork, take the right-hand path, which climbs slightly.

Red and white + orange markings

(10) At the end of the path, follow a small road to the left (marker post; ignore the yellow markings to the right). Cross a road and continue straight ahead between the fields on a grassy path. Ignore a path on the left and enter a wood. Stay on the main path, which is wide and stony, and climb up into the woods, ignoring a few paths on either side.

(11) At the crossroads (sign for "Forêt communale de Sermaise"), take the second path on the left. At the three-way junction that follows, turn right. Ignore a path coming from the right and cut across open ground towards the group of houses on the left. At the houses, follow a tarmac road to the end. At the T-junction (pond opposite), turn left onto Rue Jourdain and ignore the cul-de-sac of the same name on the left. At the next junction, turn right onto Rue de la Petite Mare and follow it for about 50 metres.

Red and white markings

(12) Take the first left, Rue du Clos Goury. At the end of the tarmac road, continue along a grassy path between the fields. Cross a copse and continue between the fields or along the edge of the woods, ignoring the paths branching off to the sides. Enter the woods again and, at the corner of a clearing on the left, turn right. Leave the woods and walk east between the fields.

Yellow markings

(13) At the T-junction, turn left (there is no yellow marker here, but there is a red and white arrow on a tree opposite on the right, which you should ignore). Descend gently towards a wood, enter the wood and descend more steeply on a stony path. The path becomes wider. Note a sandstone marker on the right-hand side indicating the direction of Saint-Chéron. Continue downhill on a sunken path which, further on, gives way to tarmac. At the T-junction, turn right. At the stop sign, continue straight ahead onto Rue du Cheval Blanc. At a fork, follow Rue du Vieux Châtres (left-hand lane) on the left-hand pavement. Walk along the left-hand side of the college buildings.

(14) At the corner of the secondary school, go down a series of small steps on the left. Walk past a nursery school on your right, then a primary school. At the corner of the primary school, turn left, go through a forest gate and walk past a football stadium on your left. Go under a small bridge and, when the tarmac road turns right, continue straight ahead on a gravel path between two hedges. At the fork that follows, turn left at a 90° angle and ignore a wooden staircase on the right. Just before the footbridge over the Orge, turn right onto a stabilised path in a wooded park (no arrow here). Walk along a pond on your right (information board) and you will come out onto a road.

No signposts

Follow the road to the left and cross the Orge one last time. At the roundabout immediately ahead, turn left onto Ruelle de l'Orge. At the corner of No. 20, turn right onto a path that climbs towards Saint-Chéron station. At the end, cross a street and you will reach the station (E).

To return home:
- RER - Line C, towards Dourdan (immediate access) or Paris (take the underground passage).

Train timetables: consult the Transilien website.

For motorists: the Dourdan and Saint-Chéron stations have car parks, so you can leave your car at one of them or one at each.

Hiking boots are required. In wet weather, some paths between fields may be muddy.

No water sources identified along the route. Bars, restaurants and shops in Dourdan, Roinville and Saint-Chéron.

A detailed map is required (at least the one accompanying this description). N.B. In order to make the urban route in Dourdan clearly legible, the scale of the first map extract has been set at 1:6,250, while the other two are at 1:25,000.

Warning:
Hikers are advised that this walk includes a significant proportion of tarmac sections.

Variations:
As this walk passes close to Sermaise station, it is possible to do only part of it, following the^GR®®1access to this station, marked in red and white, at the start or end:
- From Dourdan station to Sermaise station: 9.6km (approx. 3 hours). When you arrive in front of Sermaise church, just before (9), follow the Route de Bellanger on the left. Turn right at the first turn, onto Chemin du Pont du Bois, and cross the Orge river. At the end, turn left and you will reach Sermaise station.
- From Sermaise station to Saint-Chéron station: 7km (approx. 2 hours). Leave the station and turn left onto Avenue de Dourdan. Take the first right, Chemin du Pont du Bois. Cross the Orge river and turn left onto Route de Bellanger. You will reach Sermaise church shortly before (9).

Additional information:
This hike can be combined with the hike from Saint-Chéron to Dourdan via the hillsides on the left bank, for a circular route of around 27 km, starting either from Saint-Chéron or Dourdan.

Hike completed by the author on 7 September 2017.

- Dourdan Castle (12th-13th century) (1). Open Wednesday to Sunday and every public holiday from 10:00 to 12:00 and from 14:00 to 18:00.
- Saint-Germain-l'Auxerrois Church (12th-13th century), in Dourdan, near the castle. Open Tuesday to Sunday, from 10:00 a.m. to 6:00 p.m.
- Pleasant walk along the Orge river, particularly in Dourdan on the Promenade R. Veneau (2).
- Saint-Denis Church (12th-17th century), in Roinville (5).
- Notre-Dame de la Nativité de la Vierge Church (12th-16th century), in Sermaise (10).