Near Saint-Martin, on the D27 at a small church, take the Chemin de la Belle Étoile. Just after crossing the Riou stream, park at the Mirail water catchment car park. There are a few (limited) parking spaces in the shade. There is a yellow hiking sign and a fire hydrant.
(S/E) Head north along the tarmac road towards Mirail until you reach the DFCI water tank junction (another parking option)
(1) Continue along the tarmac road opposite and walk alongside the vineyards on your left. Reach the Mirail farm crossroads, continue on the left and, 150 metres after leaving the tarmac road, you will see an esplanade which can also be used as a car park.
(2) Go down a steep slope on the left to reach the edge of a stream, then cross it. Opposite, you will see the Mirail Spring emerging from a masonry gallery. Go back a few metres and, staying at the bottom, follow the stream, which is often dry. It gradually narrows, but you must continue at the bottom (do not try to take the paths on the right or left).
(3) Staying at the bottom, you will eventually come to a sort of inverted trident: do not take the path on the right where a small stream flows into it; it is small, but it has carved out a small cliff. Do not turn left, where the stream and a path continue towards the Bramadou ravine. Continue straight ahead, heading north on the fairly rough path that climbs and then gradually improves. Continue climbing and you will see an old abandoned sheepfold on your right.
Note: following Michel BOILLEE's advice, I have modified the text and taken a photo of this crossroads (see notice)
Continue north, gradually moving away from the stream, until you reach a right-angled crossroads.
(4) Do not take the red-marked path that branches off to the left, but turn onto the path on the right. A little further on, an intersection allows you to take a smaller but parallel path that leads to a large DFCI firebreak.
(5) Take this path on the right and continue climbing. Wind your way along the ridge to gradually reach the highest point of the walk (710m). As the forest is well maintained and pruned, the view is unobstructed.
Continue straight ahead towards the east. The path begins to descend, joining a shortcut to Bastide du Bois.
(6) Take it on the right, and the path descends more steeply towards Bastide du Bois. Shortly after the abandoned buildings, the track splits in two, but both paths rejoin further down. Continue straight ahead; the slope appears less steep. The path runs alongside a large meadow that was probably used for the Angora goats once raised at the Bastide and where there is a new DFCI water tank.
(7) Continue parallel to the ravine of the Trois Small Passes. After a 90° right turn, you will come to the first crossroads.
(1) Retrace your steps to return to the car park (S/E).