Start from Roinville church.
(S/E) Cross the D116 and continue straight ahead to the RER bridge. Pass under the bridge.
(1) At the exit, turn left and walk alongside the railway line on your left. After about 500 metres, at the Fork in the road, take the path on the right leading towards a wood. After 200 metres, enter the woodland, heading north-north-west, and climb up to the plateau.
(2) Turn right onto the Cavée Saint-Martin. Immediately afterwards, at the Fork in the road, take the path on the right. Continue along the edge of the plateau to the Chateaupers farm.
(3) After the farm, follow the small road south-east. In the hamlet of Beauvais, head back down towards Roinville and follow the Chemin de la Cavée to the right.
(4) Before the first bend (on the right), head straight down a steep path. At the bottom of the path, cross the road and walk along the edge of the field, descending at right angles to the railway line visible further down, starting from the EDF electricity pole. The old path from Beauvais to Marchais has almost disappeared (as it dates from before the railway was built), but you’ll find its remains after walking about thirty metres along the edge of the field. Join the path that runs alongside the railway line and follow it to the right.
(1) Pass under the railway bridge and head towards the church (S/E).