In Agay, head up Avenue du Gratadis, then take Route Roussivaou on the right. Pass the Esterel Caravaning campsite and head down to the Gué de la Font du Pommier car park.
(S/E) Cross the Ruisseau du Perthus and join a path in the woods opposite. Follow this path uphill to the left, keeping to the stream. At the fork, go straight on.
(1) Cross the Ravin du Bagnolin and climb the slope opposite via a path through the slate. Ignore a path leading down to the left, then turn right onto a path that follows the ridge: view of Les Perthus. At the large rock, continue along the ridge
(2) Turn left at the junction.
(3) At the junction of five paths, take the one opposite marked in yellow.
(4) At the T-junction, turn right, then turn left about a hundred metres further on.
(5) Where the path approaches the road (about 20 m), head down to it via a path not shown on the map. Cross the road and take the path opposite that leads down towards the Ravin du Gratadis. Follow the stream and pass by a pretty little lake.
(6) At Col Aubert, turn left.
(7) At Col du Baladou, cross the wide track and climb the path opposite.
(8) At Col du Perthus, turn left onto the path leading down. At the T-junction, turn left. Pass by the summit of Pic du Perthus Oriental and follow the path down. Once back on the wide path you crossed earlier, turn left.
(9) At Col du Mistral, head down the path on the right: a shortcut not shown on the IGN map but present on OSM Trails. Continue along the road to the right. Cross the Perthus bridge and take the Ravin du Perthus path on the right.
(10) After about 200 m, take the hairpin bend onto the path on the left. Ignore a path on the right. Turn right, then left after a climb. Further on, turn right and cross a concrete slab at the Vallon de l'Amandier.
(11) At the junction not far from the Roussivau Forest House, go straight on.
(12) Take the hairpin bend to the left. Then turn right onto the wide path and cross the Pont de Sigallon.
(13) At the right-hand bend, take the path down to the left and cross the stream in the Vallon de l'Apié de Sigallon. Shortly afterwards, turn right. At the clump of eucalyptus trees, continue along the path that leads downhill. At the left-hand bend, take the short path down to the right to reach the road. Turn right and head to the car park (S/E).
. But after that, there were no major difficulties.