Park at Col de Portet.
(S/E) Set off along a steep track climbing north-west, then veering right at the top station of the Col ski lift. Follow it to its summit near the top station of the Aulon chairlift.
(1) Leave the track at a hairpin bend and take a path opposite. Climb straight up onto the ridge, where you’ll need to use your hands a little. You’ll reach a somewhat vertiginous viewpoint, then descend an easy scree slope. The path often follows the ridge, sometimes running along the left-hand side, passing directly below the Pic de Montarrouyes and then the Montarrouyet. Reach the Col de Jétas.
(2) Continue along the ridge to reach the summit of Pichaley without difficulty: there is a magnificent view of the many lakes from this summit.
(3) Continue along the ridge to descend to the Col de Bastan: this descent can be made via various routes, some of which are very steep if you choose your path unwisely.
(4) Descend to the left towards the Upper Bastan Lake.
(5) Turn right to head towards the lake’s shores and reach the outlet.
(6) Turn right onto theGR®10C(red and white markings) and head back up to the junction marking the start of the circular loop you are about to complete.
(7) Turn right and head straight north. You’ll reach the Col de Bastanet.
(8) Climb the ridge to the left on a path that is easy at the start.
(9) The going gets trickier. You have the choice between sections of path along the edge – which are exposed – and small rocky chimneys: I preferred the latter. Reach the summit of the Pic de Bastan.
(10) Enjoy the magnificent 360° view, then begin the descent back to the Col de Bastanet.
(8) Turn left towards Lac de la Hourquette, rejoining the GR®.
(11) Leave theGR®10C, head left towards the west and climb up to the Hourquette de Caderolles.
(12) Descend on the other side towards Lac de Bastan or Port Bielh and reach a junction before arriving there.
(13) Follow the path on the left which descends to a hut situated near several small lakes.
(14) Carry on to the left to climb back up towards the Lacs de Bastanet. Pass the second and smaller of the two lakes and return to the junction where the circular route begins, rejoining the GR®.
(7) Turn right and walk along the Lac Supérieur.
(6) Head right, due south, and reach the Refuge de Bastan.
(15) Continue downhill alongside Lac du Milieu. Pass two small lakes and reach a junction where a rock on the ground is marked ‘Col du Portet’ to the left.
(16) Leave theGR®10C, turn left and continue the descent, following the path which heads first due south then south-east , offering stunning views of Lac de l’Oule.
(17) Join theGR®10and continue due south.
(18) Leave theGR®10, keep to the left, and join a track which you follow to the left as far as the Col de Portet (S/E).