Park in Dreuilhe, in the car park under the trees opposite an old factory.
(S/E) With your back to the car park, head south for 200 metres and turn left onto Chemin de la Bouyche, heading south-east, following the GR® de Pays d'Olmes: yellow and red markings. Stay on this path, keeping the same direction, pass the hamlet of La Bouyche and reach Ivry sur l'Hers.
(1) Turn right and carefully follow the D16 for about 400 m. Turn left towards Camp Redon and cross the hamlet: old horn comb factories. Continue along the road.
(2) After the last houses, take the path that climbs left into the woods. Leave the GR® de Pays trail on your right and continue straight ahead. Walk along the Hers river and reach Fontcirgue.
(3) At the pumping station, go straight ahead, following the Chemin de Bel Air to the entrance to Bastide-sur-l'Hers at the Los Lobios housing estate
(4) Turn left, continuing to follow the Hers, then cross the bridge on the left.
(5) Turn right to reach Place de la Liberté, first turn left then right onto Rue Léopold Bonnet, then turn left onto Rue Louis Pasteur. Walk along the temple, follow Rue Saint-Roch to the right and reach the intersection with Chemin des Cimetières.
(6) Go straight ahead, pass in front of the Protestant cemetery and continue along the road, then take the path that climbs up to the RD16. Turn right and follow this road for a few dozen metres to reach the Col du Perrinet.
(7) Take the path on the left heading west, which winds along the ridge under the trees.
(8) Pass under the Saint-Roch Chapel (view of Lake Montbel) and follow the path down to Laroque-d'Olmes.
(9) At the church, turn left and go down Rue de l'Église. When you reach Rue Marcel Cerdan, turn right and walk along the left side of Place de la Cabanette for about 30 metres, then first turn left then right to join the D620.
(10) Follow it to the left until you reach the three-way junction before a group of houses.
(11) Turn right to follow the Touyre river.
(12) At the crossroads before reaching Concu Ruch, turn right under the Greenway and follow the path that runs alongside the Touyre before rejoining it.
(13) Cross the Greenway (former SNCF railway line) and continue along Chemin du Touyre to return to the car park (S/E).