Start from the car park at Monthermé river port, motorhome area.
(S/E) Head towards the bridge over the Meuse and cross it.
(1) After the bridge, turn left to follow the towpath along the Meuse for about 300 metres. After the houses, cross the road on your right towards the hills and follow the GR®12C uphill through the forest to reach a crossroads.
(2) Still on the GR®12C, turn sharply right and follow the signpost indicating the ridge path to the Longue Roche viewpoint, then on to the Roche à Sept Heures, a magnificent viewpoint overlooking the Meuse valley. Continue along the forest track for about 400 metres to the junction with the D989.
(3) About ten metres before the road, take a path on the right, passing by the restaurant, to follow the Chemin des Hautes Buttes towards the pylons.
(4) Just before reaching the road, take a sharp right-hand bend onto a small grassy path that descends for 200 metres to Rue Monseigneur Bihery (D989). Head slightly to the left down the sloping street (Rue de la Promenade), continue straight on into Rue Georges Guynemer, which runs alongside the cemetery, then turn right into Rue Maryse Bastié, passing the secondary school on your left. 150 metres further on, turn right into Rue Héléne Boucher, then right again to head towards the centre of Monthermé via Rue du Docteur Lemaire. Walk for about 50 metres.
(5) Turn left into Rue André Compain – this is also the GR®12C – heading towards the campsite whilst walking alongside the factory on your right. After crossing two branches of the Semois, you’ll reach a Fork in the road.
(6) Continue to follow the GR®12C round a hairpin bend to the left, then, 75 metres further on, turn right and head uphill through the forest for about 1 kilometre until you reach a crossroads (rest area).
(7) Make a zigzag turn, pass the Roche Bayard viewpoint and continue straight on to the Quatre Fils Aymon, a viewpoint overlooking Bogny. Continue downhill until you reach the end of a small road.
(8) Take the steps opposite and head down towards Château Regnault until you reach Rue Léon Bosquet. Turn left, follow Rue de la Légende for about a hundred metres, then turn right onto Rue Maugis. Turn left into Rue de la Rochette, then, after 20 metres, turn right down Rue des Juifs until you reach the steps leading to the bridge over the Meuse. Cross the bridge and walk past the school.
(9) After 60 metres, turn right onto Rue de l’Hermitage, which climbs for 600 metres, until you reach a hairpin bend.
(10) Turn right onto the road leading towards a scrap metal monument. Leave the monument on your right and head straight up towards the ridge along a steep path leading to the Roche aux Sept Villages. Enjoy the view and continue on to reach the D989.
(11) Cross the D989 road (take care) whilst following the GR®12C to rejoin it further on.
(12) Follow the road to the left for 150 metres, then turn right onto a path called ‘le Vieux Chemin’, which descends towards Monthermé. Join the Chemin des Ecaillettes and follow it to the D989.
(13) Turn right towards the Meuse to reach the river port on your right and the starting car park (S/E).

In fact, the last climb and especially the descent were too much for my old joints. I must admit that, with the dead leaves and slate on the ground, this was the part I found most slippery.