The walk starts at the church in Maudétour-en-Vexin. There is no car park, but you can easily park on Route de la Grand'Mare.
(S/E) With your back to the church, go straight ahead and then turn left onto Route des Moines. At the fork, go down to the right until you reach the sign marking the end of Maudétour en Vexin (ignore Chemin Neuf on the right).
(1) At the site of an old calvary still marked on the IGN map, turn left onto a wide gravel path marked for bicycles. Continue straight ahead (west) and, after a good 1.5 km, you will reach the D 147.
(2) Cross the road and immediately take the path furthest to the right, which leads into the woods (yellow markings). Continue straight ahead on the marked path dotted with hunting towers, ignoring all the side paths. After about 1.5 km, you will come to a clearly marked crossroads.
(3) Turn right onto a fairly wide path, still in the woods. At the edge of the woods, take thesecond path on the right, along the edge of the woods, and walk alongside a field on your left for about 200 m.
(4) Take the path that branches off to the left (north-west) between two fields. At the end of the path, turn right (signs explain the work in the Villarceaux sheepfold; situation as of May 2020). Continue straight ahead (east-north-east) for about 1 km.
(5) At thefirst fork, turn left. At thesecond fork, shortly after entering the undergrowth, take the path on the right, which descends.
(6) Ignore a path coming from the right and continue downhill. Cross a small stream via a wooden bridge. Continue uphill and exit the woods. At the crossroads, follow the road uphill to the right and pass the cemetery.
(7) Shortly afterwards, just before the entrance to a right-hand bend, turn left onto a small path that descends. Start in the undergrowth and continue along the edge of the woods.
(8) Cross Rue du Vieux Moulin (D 147) and head towards a small gravel square surrounded by houses. At the end, on the right, take a path between two houses (red and white markings). Wind your way between the houses, cross the Ru de Genainville and go uphill to reach Rue de la Sérée.
(9) Turn right onto this street and pass by a wash house. At the next crossroads, follow Rue Porcheron almost opposite. Continue along this street, which gradually turns into a path.
(10) At the fork, turn right onto the path through the woods. Walk alongside a small stream on your right. A little further on, note the Gallo-Roman site on your right, which is currently being excavated and is closed to the public. The path runs alongside the fence bordering this site, allowing you to see the ruins quite clearly. At the end of the fence, the path widens and enters the woods.
(11) At a barrier, turn right (red and white markings). Climb up a poorly maintained but passable path (May 2020). At the top, continue south-southwest on a perfectly decent path between the fields. Pass a cemetery.
(12) You will come to a small road; follow it to the right. Continue straight ahead to the starting point (S/E).
