Park in the car park at the Roussivau Forest House.
(S/E) Take the paved road eastwards, along the Maison Forestière. Approach the Ruisseau du Perthus before reaching a picnic area.
(1) Begin a slight climb towards the Perthus bridge by taking the path on the left.
At the first fork, keep right and at the next fork, keep left to follow the Ravin du Perthus.
After passing the bridge, turn left to begin the climb. At the top, turn left and continue to the crossroads with the track leading to the peak.
(2) Take this on the left to reach the Pic du Perthus Occidental, which offers a remarkable view.
(3) Return by the same route to the previous crossroads.
(2) Stay on the track, passing close to two cisterns. Shortly after the second one, you will reach the Baisse Andoulette crossroads.
(4) Leave the track on the left for 50 metres, then take the path that descends to the left. After a hairpin bend to the right, you will come to a fork in the path.
(5) Turn right and quickly rejoin a track, which is the Castelli track. Turn left onto it. Cross the stream over a bridge and return to the Roussivau forest house (S/E).