From Saint-Chinian, take the D 20E1, then the D20 towards Cessenon-sur-Orb. At the roundabout before this village, turn left towards Roquebrun and Vieussan. Beyond this, after crossing a beautiful suspension bridge, you will arrive at the intersection with the D 908. Turn right and a few hundred metres further on, head towards Saint-Martin-de-l'Arçon (village centre). The dead-end road climbs up to the village, passing in front of the church and the cemetery. Continue for a few metres and park on the esplanade on the left-hand side of the road.
Yellow markings
(S/E) From the parking spot, walk back down the road a few metres and turn right onto the tarmac road that leads to the hamlet of La Coste and the bottom of the Gorges d'Héric.
Yellow and red markings
(1) When you reach the stream, leave the "Pont des Soupirs" bridge on your left and start climbing the Sentier des Gardes trail to the Col de Bartouyre pass (altitude 677 m). When you reach the pass, turn right to admire the view.
(2) The trail, now level (which is welcome after the climb), turns left, soon passing four enormous pyramid-shaped cairns to reach the Croix Saint-Martin intersection.
(3) Continue straight ahead on the GRP® marked in yellow and red. The markings are quite difficult to follow along this section of the trail. Fortunately, the few markings are supplemented by cairns and blue paint circles. There are a few tricky (but safe) passages along the way.
(4) Intersection (signs on tree) at Saut de l'Âne. Pass a ledge on the right that leads to the village of Saint-Martin-de-l'Arçon (this route is not obvious but is marked with cairns and yellow circles). But continue straight ahead through this magnificent mineral world, passing the Portail des Cades (elevation 830, a short tunnel formed by an enormous rock). The descent that follows is quite unpleasant on a slope formed of small boulders and scree (be careful to follow the trail). The path returns to normal. The going is a little exposed, but not difficult. Continue to follow the GRP® markings to Roc du Boutou. A larger cairn next to a yellow/red marker indicates the intersection of an ascending path on the left. Please note: this is not very easy to see. Leave the GRP®.
No markings
(5) Turn left (yellow/red cross, approx. 780 m altitude). From this point, the climb is steady through the holm oaks. Follow the cairns and a few rare, barely visible yellow markers. At an altitude of around 920 m, a long horizontal traverse leads to the foot of a cliff, at the base of which the climb resumes, finally levelling out at a beech forest where you will find a well-marked, more horizontal path to Roc de Boutou.
(6) At a huge pyramid-shaped cairn at the edge of the ravine, turn left at a 90° angle to follow a path that climbs slightly through a pine forest and arrives at a T-junction with the GR® 7 marked in white/red.
White and red markings
(7) Follow the GR®7 trail to the left, which heads south to a viewpointwith an orientation table offering a magnificent view of the hills to the south and the Minervois region as far as the Corbières, the sea and the Pyrenees.
(8) Leave the viewpoint by following the markings to the right, heading north-north-west, then roughly west. At the next trail junction, leave the markings and head left towards the "Sentier des Gardes" (signposted). The cairned trail descends towards Rochet de Lucet (new sign: Sentier des Gardes). The winding descent continues through boulders, generally heading south. With few markings (cairns and red dots are not very visible), it leads to the intersection of the Croix de Saint-Martin, which you passed on the way there.
Yellow markings
(3) The sign indicates Saint-Martin-de-l'Arçon: 1 hour. Leave the GRP® and descend straight down this well-marked PR® through holm oaks and chestnut trees. A footbridge allows you to cross a large ravine where a large torrent (Ruisseau de Saint-Martin) sometimes flows. You will then arrive at Mas le Plus Haut. Cross it via charming little streets lined with pretty, tastefully restored stone houses. Continue opposite, following the yellow markings through the maze of streets to return to the car park (S/E).