From Achères to Achères via the Forêt de Saint-Germain and the Étang du Corra

Departure point and access: Achères-Ville station.
- RER - Line A, on the section between Paris and Cergy.
Take the night exit on track 2 in the direction from Cergy to Paris (if arriving in the opposite direction, on track 1, use the subway).

Unmarked

(S) On leaving the station, cross a road at the pedestrian crossing and follow it to the left. At the corner of the building, turn right into Allée de la Lisière Saint-Jean. Walk past the foot of the buildings, head towards the forest and come to an information board.

Red and yellow signs

At the foot of the sign, turn right and enter the forest. When you come to a three-way junction, turn left and climb gently. At the next crossroads (mountain bike signposts), turn right. At the crossroads (Étoile du Maine), go straight on to the next crossroads (Étoile des Carrières d'Achères).

(1) Take the^2nd track on the left. Go south-east and cross a path. Cross a road and continue along the track opposite (the one furthest to the left). After about 300 m, you will come to a crossroads (be careful not to miss it).

(2) Follow a path to the left that goes deep into the forest. Wind through the undergrowth until you reach a crossroads. Follow the main road to the right (ignore the ^1st on the right, which gives access to the Cité Coligny). Just before a road bridge, cross the road at the pedestrian crossing and then go under the bridge.

(3) Immediately afterwards, turn left onto a path that enters the forest(be careful to spot the start of the path). Immediately turn right and meander through the undergrowth, ignoring the tracks on the sides(the mauve line that is supposed to show the path on the map is inaccurate here, but the GPS track is adjusted to the OSM base map). At the end, cross a road, immediately turn right onto an old road and reach the next crossroads.

(4) Turn left, go through a forest fence and follow a tarmac track to the north. After approximately 500 m, turn right onto a narrower tarmac track. Go straight ahead until you reach a crossroads (abandoned forest house).

No signposting

(5) Then take the^1st relatively narrow track on the left. At the^1st crossroads, turn right and follow a path through dense forest cover. Go straight ahead until you come to a junction with a well-marked path. Turn left at this point. Ignore a path coming from the right and turn right at the next crossroads. At the crossroads, go straight ahead and descend.

(6) At the bottom of the hill, at a T-junction, turn left onto a wide track and follow the Etang du Corrat on your right, glimpsed between the branches. Go through a forest fence and veer right to keep as close as possible to the pond. Further on, leave a shelter on your left, stay on the main path close to a road and follow a car park on your left. At the end of the car park, turn right and stay as close as possible to the pond.

Red and yellow markings

Head east along a small beach and then the north shore of the lake. There are two parallel paths that meet further on: take the one closest to the pond.

(7) Go down a flight of steps on the right to reach a small pontoon. Take this as close to the water as possible. At the end, go back up and follow the main path again, skirting a wall on your left. At a signpost, turn right, still on the edge of the pond. At a large T-junction (information panel), turn left and you will soon come to a crossroads.

No signposting

(8) Go straight ahead (east) along a wide track. At the next crossroads (mountain bike signposts), turn left and at the crossroads opposite an opening in a wall, turn right (do not go through the wall). At the fork in the wall, take the right-hand path. Go east-south-east through dense undergrowth and successively cross a faint path, a sandy track (Route de la Garenne) and another track (Route de la Muette). Then cross a wide track (Route de Brige) and continue along the path through a more open woodland.

(9) At the crossroads, take the^2nd track on the right, almost straight ahead (south-south-east). At the next crossroads (Étoile du Bout du Monde), go straight on and at the next crossroads a hundred metres further on, go straight on for another thirty metres or so.

Yellow markings

(10) Then turn left onto a path that enters the forest(be careful to spot the start of the path). Keep to the main path, ignoring several tracks on the sides and follow the markings(here again, the Mauve line on the IGN is inaccurate). Further on, keep parallel to a wider track on the left. Come out onto a wide track and follow it to the right.

Yellow signposting + Green signposting on a white background (in the opposite direction to walking).

(11) At the end, cross a road at the pedestrian crossing and join a car park on the right, passing under a metal gate. At the end of the car park, there are two parallel paths: choose the one on the left and leave a forestry barrier on the right. After a bench on the right, take the^1st path on the left. Cross a level track and continue straight ahead. At the T-junction, turn right, then ignore a path on the left that is not shown on the IGN and immediately reach a crossroads.

Yellow markings

(12) Turn left and then left again at the junction shortly afterwards. Go right along a high embankment. You will come to a track, follow it to the right and cross the bridge over the railway line. At the end of the bridge, continue straight ahead (south-west). At the next crossroads, go straight ahead again, skirting a small clearing and coming to a crossroads.

Red and yellow markings

(13) Turn right at this point: there are two parallel paths, and the route on the map follows the left-hand path, which is the wider of the two. At the next crossroads, go straight ahead and descend. Head due west and successively cross four perpendicular paths. You will come to a crossroads.

Unmarked

(14) Take the^2nd path on the left and walk past a tree on the left-hand side, bearing number 126. At the^1st crossroads, go straight ahead and at the^2nd, turn right (yellow cross). Go straight on at the next crossroads.

Yellow markings

(15) At the crossroads (plot no. 124), turn right. At the next crossroads (plot no. 122), go straight ahead. At the crossroads (Étoile des Palis Ferrand), go straight ahead and reach the next crossroads (stone cross).

(16) Cross the tarmac road and continue along the track opposite (MTB signpost). At the end, take a left-right turn along the busy N184. The Achères-Grand Cormier train station (E) is on the right.

To get back home:
- RER - Line A, towards Paris or Poissy.

Train timetables: consult the Transilien website.

For motorists:
Park either in the Étang du Corra car park, between (6) and (7), or in the Étoile des Pétrons car park (11). Make a loop as suggested in the variant below.

Hiking boots useful.

There are no water points along the route.

Detailed map required (at least the one that accompanies this description).

Variation:
This walk can be done as a loop starting from Achères-Grand Cormier station (E). Take the only exit at the head of the train when coming from Paris. Exit along the N184 and follow it to the right over the bridge that spans the railway tracks. On the other side, go down a flight of steps that joins a road. Start the walk at3. Allow around 13.5 km for this shorter version.

Walk made by the author on 20 May 2023.

- Pleasant woodland walks, with alternating paths under dense cover and wider, airier paths.
- Étang du Corra (protected site).