Start: Place de la Mairie (Town hall square), Nœux-lès-Auxi.
(S/E) Pass the church and turn left onto Rue de Villers. Pass under the very high bridge and turn right onto a wide road.
(1) After 150m, turn right to join the old railroad line (GR® Canche-Authie, marked in yellow and red). Follow the track to the left. Cross the D117 over a bridge, pass a company, cross a small road and reach the D938.
(2) Cross it and find the continuation of the railroad opposite. About 500 m further on, at the crossroads, turn left to join the Authie river. Pass the chain and turn right along the river.
I've taken the shortest route, but you can have fun following all the twists and turns if you please.
(3) Shortly after a pretty picnic area (tables), reach Pont Rouge. Turn right to pass the waste disposal site and reach the D938. Cross this road and turn slightly right onto a small road that leads to Cité Foch. Take the opposite street, which veers left and reaches a T-junction. Turn right and cross the plain diagonally (there's a path) to reach the D941 at the highest point.
Follow it to the left for a few metres, then turn right into Rue du Soleil. Just after number 24, take the small road on the right. Cross the grassy area to reach a tarmac lane. Turn right into Rue de Nœux. Turn right onto the D941.
(5) Follow this for a few metres to the left, before turning right onto the wide grassy track (Chemin de Nœux), first at the edge of a field, then at the edge and finally in the undergrowth (ignore a track leading off to the right). 1500m further on, again at the edge of the field, turn right between two fields to reach the "Tête de Nœux" (hill 121).
(6) Turn left at a hairpin bend and follow the wide path to the road (Rue de Buire). Reach the Notre-Dame de Liesse chapel (with "culs de bouteilles" crosses).
(7) Following the signposts, take the path on your left (when you're opposite the chapel, the path is on your right). It gets closer to the road, but there's a very pleasant extension which eventually rejoins the road.
(8) Follow it uphill to the right (outside the growing season, you can stay in the field and walk along the hedge).
(9) At the left-hand bend, leave the road to take the large track on the right. Reach Mont d'Hesdin. The path twists and turns, eventually reaching a T-junction.
(10) Take the pretty climb to the left. Pass under the power line and reach a fork. Turn right for a few metres.
(11) The entrance to the Ravin des Cavernes is there (starred arrow). Difficult descent at the start (string on the left), then a steep path lined with beautiful ravine ferns and ferns. Continue downhill to the edge of the wood. The ravine was well cleaned in spring 2022, but it's still a difficult, narrow trail
(a little taste of adventure!!!)
(12) Turn left onto a grassy path, heading for a large explanatory sign. A wooden fence marks the entrance to the moor.
This part is difficult to describe due to the large number of paths. Basically, go right after the barrier and follow the fence on a narrow path (preferably the best-marked one) to the north-east. The next gates are against the fence.
When you see the quarry, go slightly uphill to pass over it.
Climb down a rustic staircase to reach the 4th and last barrier (another explanatory sign).
(13) Go through the barrier and follow the grassy path between the fences. Reach the small road and follow it to the right for 600m.
(14) At the crossroads, take the path rising to the left (starred arrow). It veers left, then right, and reaches a crossroads where the GR® Canche-Authie can be found.
(15) Follow it to the right until you reach a picnic area.
(16) Leave the GR® and take the small road opposite. You will then reach the Rue de Villers, which you follow to the right. Pass under the high bridge at the start and descend to Nœux (S/E).