Update by the author on 11/12/2025:
- The route was slightly incorrect just before point (1): it has been corrected.
- The point (17) has been moved back to the intersection. The short section of the route towards the cave has been removed.
The route starts from the car park at the Moliets footbridge in the commune of Thorens-Glières. Access via the RD55 road towards the Plateau des Glières, then the Route de la Verrerie after the village of Nant-Sec, then the Chemin de l'Adiau until its final 500 m, which are unpaved.
Please note that since 17/10/2025, access to the Verrerie bridge has been prohibited to motor vehicles until further notice (while consolidation work is carried out):the starting point of the hike must temporarily be a little earlier, from the hamlet of La Verrerie (additional distance for the round trip = approximately 1.5 km).
(S/E) Cross the footbridge towards the Plateau des Glières. Continue to the intersection.
(1) Continue straight ahead, following the marked route at the few intersections.
(2) Shortly after crossing a footbridge, continue straight ahead until you reach another path.
(3) Join a path and follow it to the left until you reach the chalets (a place called Traversy).
(4) Just after reaching a road, continue straight ahead on it. You will arrive at a place called Dran.
(5) Continue straight ahead towards La Rosière. At the Notre-Dame des Neiges chapel, continue straight ahead for 100 metres.
(6) Leave the track and follow a path on the right that is not very well marked at the start (there is a cairn), then continue along the route, which then turns right and left and includes a few rough sections. Follow the yellow markings. Reach the ridge: be careful to spot an intersection that is not very visible.
(7) Head left, following the yellow markings and cairns as best you can. Next, cross two sharp limestone pavement areas, keeping to the right (there are also some markings). Reach the summit of Tête Noire (nice view).
(8) Continue straight ahead, following the descending path. Shortly afterwards, you will encounter a difficult section where you will need to use your hands to descend a chimney.
(9) Continue downhill until you reach an intersection.
(10) Continue straight ahead. You will arrive at the summit of Tête d'Arpettaz, topped by a cross (very beautiful views).
(11) Retrace your steps to the intersection you passed just before.
(10) Turn left. After a long descent, you will reach the Gorge d'Ablon: continue to the right, then join another path and follow it straight ahead until you reach an intersection.
(12) Follow the path uphill to the left (towards Col du Pertuis) over somewhat rugged terrain in a rocky environment. Along the way, bear right to join another path that leads to the ridge, then continue on a gently sloping route until you reach a section of sharp limestone pavement, which you will cross. You will arrive at the Croix du Bénitier.
(13) Continue straight ahead on a path that slopes downwards. Further down, join another path and continue straight ahead until you reach the intersection before Col du Pertuis (which is actually a little further on).
(14) Turn right towards Alpage du Pertuis. After passing Croix Pradier, you will arrive at a large meadow.
(15) At the junction, continue right towards the Fontaine du Geai, passing through a wooded area.
(16) Pass a chalet and continue straight ahead, passing a shelter. Continue straight ahead at the intersection not far from the Fontaine du Geai.
(17) Turn right onto a discreet path leading to a hut in less than 5 minutes (shelter if needed).
(18) Continue along the route, tackling a few difficult passages a little further on that require a minimum of caution.
(19) Further down, at an intersection, continue to the right (on the left, it is possible to make a round trip to the Grotte de la Diau). Return to the initial fork.
(1) Turn left and you will soon reach the starting point (S/E).