From Pontoise to Conflans along the river

(S) Starting point: Pontoise SNCF station. Take the Gare routière / Canrobert exit, then head towards Avenue Maréchal Canrobert. Walk down the avenue, then take the^first left-hand lane after the SNCF operations centre at the Pont de l’Oise. Follow the Viosne river until you reach Avenue du Général Gabriel Delarue (D14). Cross at the traffic lights.

GRP® (red and yellow markings)

(1) Turn right onto Chemin de la Pelouse, which runs alongside the River Oise; go under the A15 bridge, then cross through Parc des Larris, which is dominated by sheep pastures.

PR® (yellow markings)

(2) On leaving the park, leave the GRP®. Follow the PR® which passes under a road bridge, then under the RER tracks, emerging onto Boulevard des Maraîchers. Walk alongside the farm until the end of the boulevard, where it becomes a tarmac road, then turn right towards the Bois de la Balastière.

(3) The PR® soon turns left, before the retractable bollard marking the entrance to the woods.Follow the signposting carefully until you reach the exit of the woods, particularly as the maps are partly incomplete in this area. Pass the first junction, then, at the fork in the road, turn right to join a wide path. Follow it to the left, then, at the next junction, turn right. Next, turn left onto a less visible path that winds its way through the trees, before climbing a small hill. Carry on straight ahead before descending to a T-junction, then turn right. At the next junction, join the path that runs to the left of a double track (two paths separated by a hedge). Continue along this path, then turn left at the fork in the road until you reach the corner of an elevated clearing.

(4) Walk along the edge of the clearing on the left, then, at the opposite corner, carry on straight ahead. Stay on this path, ignoring any side tracks, until you reach a fence bordering private properties. Walk alongside them on your left until you reach a tarmac road, Allée des Plantes. Follow it up to a junction, then turn left onto Chemin Neuf until you reach the River Oise. Turn right under the road bridge.

(5) Continue straight on along Avenue Jean Bart to reach Port Cergy. Pass under a large archway, then cross the bridge on the left.

No signposting within the Île de loisirs

(6) At the end of the bridge, continue up the steps, then straight ahead, where the PR® sign is blocked off. At^{the second junction} , turn right onto the wide path leading to the Axe Majeur footbridge.

(7) Cross the footbridge, then follow the Axe Majeur upstream to the GRP® on the former Voie du Tacot.

GRP® (red and yellow markings)

(8) Follow the path to the left until you reach Rue de l’Ancienne Mairie. Cross at the pedestrian crossing, turn left, then right onto Rue Neuve. A little further on, turn right onto the path between the houses, then turn left onto Impasse Jules Bourgain. At the junction, take Rue de l’Église on the right, then the^first path on the left. As you come out of the woods, take the path on the left.

(9) After the covered walkway known as the ‘Cimetière des Anglais’, continue straight on to the car park by the pétanque court. Just after this – be careful, as the signposting is misleading – turn right, then immediately left onto the tarmac track, heading towards the Promenade des Loctaines. Further on, there is a viewpoint on the left (suitable for a picnic).

(10) At the end of the promenade, take the Chemin du Dessus des Villettes opposite you until you reach the T-junction, then turn right onto Rue des Valanchards. Cross at the pedestrian crossing, then turn left towards the car park (canopy). Continue along the GRP®; do not head towards the sports ground. At the Fork in the road, turn right, then right again. Go down the stairs via several hairpin bends, then cross the footbridge.

Unmarked

(11) On the way back up, turn left, leaving the GRP® on your right, then go straight on until you reach the cul-de-sac (housing estate). At the junction, turn left. Cross Rue de la Vallée and take the steps opposite. At the very last step, turn left onto a wide path. Pass the concrete blocks, walk alongside the houses on the edge of the forest, then cross a clearing. Continue through the forest until you reach the (tarmac) Chemin des Marlènes. Walk up it, then continue along the road opposite. Cross at the pedestrian crossing. Take the wide path opposite, running alongside the houses. Pass two paths on the left. At^{the third}, head straight down to a clearing which leads onto the old (tarmac) Voie du Tacot.

PR® (yellow markings)

(12) Turn right, then carry on straight ahead. Cross the Boulevard d’Ecancourt. Cut across the^first street, then the^second.

Unmarked

(13) Take the path opposite and continue across the fields. At Impasse Paul-Émile Victor, turn immediately right onto a footpath, then continue straight on to Maurecourt Cemetery. Go round the left-hand side of the cemetery before coming out onto a street; turn right onto this street, following the cemetery wall. At the junction, cross the street.

GRP® (red and yellow markings)

(14) Take the wide, earthen path that runs between the houses. Continue straight on until you reach the River Oise. Turn right until you reach a street (Quai Boubou Dado). Follow the quay to Andrésy, pass under the Eiffel railway bridge and reach the road bridge.

GR® (red and white markings)

(15) Turn right onto the pedestrian ramp leading to the bridge, cross the River Oise, then go down the pedestrian ramp on the opposite bank. Pass under the bridge, then cross towards the confluence of the River Oise and the River Seine.

(16) Walk past the monument. Follow the quay which passes under the RER bridge, then the N184 bridge, followed by a footbridge, before continuing along the Promenade François Mitterrand.

(17) Carry on straight ahead, noting the ‘Je sers’ chapel boat, and head for Place Fouillère, a wooden esplanade and part of the city’s discovery trail. Continue to Port Saint-Nicolas.

No signposting

(18) At the two low concrete walls flanking the flowerbeds, take the small flight of steps (restaurant opposite). Cross the road (pedestrian crossing), turn left for a few metres, then right onto Ruelle de la Chaussée. Go up the steps, then turn left onto Rue de la Savaterie. At the Fork in the road, turn right, then right again towards the square.

(19) Walk along the right-hand side of Saint-Maclou Church until you reach Place Jules Gévelot. Walk round it, then enter the courtyard of the Musée de la Batellerie at the Château du Prieuré.

(20) Walk under the building to enter the Parc du Prieuré (open 7 days a week from 7.30 am to 8.30 pm or 10.00 pm depending on the season). Turn left, then right in front of the greenhouse, then left. Go down the grand staircase to leave the park. Turn right onto Rue Pasteur. After the bend, turn left onto Passage des Fondées, then immediately left again. Go up the stairs, continue straight ahead until you reach Avenue Jean-Jaurès. Turn right to reach Conflans railway station (E) (Line J – direct connection to Pontoise station).

For motorists: both stations are situated on the same section of the Transilien Line J. You can park near either station and take a train there or back to reach the starting point of the route.

You can shorten the route at Conflans-Fin-d’Oise near the ‘16 ’ (RER A / Line J, 1 change to return to Pontoise).

Hiking boots, detailed maps and/or a GPS are essential.

There are plenty of places to stop for a picnic, but no water sources have been identified along the route.

Between (5) and (6) the village of Cergy (church, porch) near Port Cergy.

(7) Axe Majeur, a work by the architect Dany Karavan.

(8) The ‘Tacot’ route (former Pontoise–Poissy railway line) http://philgene.free.fr/train/cgb_pontoise_poissy.html.

(16) “Fin d’Oise” confluence: War Memorial to those who died in the river transport industry.

(17) ‘Je sers’ River Chapel, parish of the River Boatmen.

(19) Saint-Maclou Church, Conflans-Ste-Honorine.

(20) River Transport Museum and its grounds, Conflans-Ste-Honorine.