Access: Saint-Quentin car park (limited to around ten cars). It can be reached from Soumont Saint-Quentin by taking the D261B, which leaves from the village church and descends towards the Laizon gorge. The car park is on the left just after crossing the Laizon.
(S/E) Take the path opposite the car park on the other side of the D261B towards the Brèche au Diable. Walk 300 metres along the Laizon river and, at the waterfall, keep left, following the yellow signs for the Brèche au Diable trail. The path runs alongside the woods for 300 metres, then crosses them, turning sharply right to arrive at the Saint Quentin chapel.
(1) Take the tarmac road on the left for 50 metres, then take the path that descends to the right to join another path. Continue downhill to the right to reach the Laizon and cross it via a wooden bridge, the Pont du Lavoir.
(2) After the sign for the site, climb the path on the left that winds through the gorge. At the crossroads, turn left to the edge of the forest and follow it on the right for 200 metres, then turn left and right and head towards the farms.
(3) At the crossroads, turn right, then continue straight ahead towards the woods. In the woods, continue straight ahead, leaving the paths on your right and left, until you reach the D261, near an old wood drying building.
(4) Go down to the right for 100m on the D261B, then follow the path opposite which climbs gently towards Ouilly-le-Tesson, following the yellow markings. Pass a water treatment plant.
(5) At the first houses in Ouilly-le-Tesson, turn left and then immediately right to go up towards the church.
(6) At the church in Ouilly-le-Tesson, follow the D261 for 1 km, passing the calvary.
(7) Before a Y-junction, take the road on the right. Go down the road that crosses the Laizon. Continue to follow the yellow signs on the right at the crossroads.
(8) After the farm building, turn left onto the path that climbs alongside the fields, then take the first path on the right that joins the Chemin du Bois des Plaids and leads to the D261A.
(9) Follow the D261A to the left for 100 m, then turn right onto the path leading down to Saint-Quentin. Access is restricted to pedestrians. This path leads to the top of the Chemin du Mont Robert, which winds around the houses of Saint-Quentin and descends to the Saint Quentin road (D261B). Turn right and descend gently to reach the car park (S/E).