The car park is located just after the Blanches-Fontaines art foundry south of Undervelier on the left-hand side of the road after the bridge over the Sorne.
(S/E) From the car park, follow the marked path on the right towards the Sorne and walk upstream.
(1) Go around the lake on the left.
(2) Cross a ford and continue on the right bank of the Sorne, then start a steep climb towards the road.
(3) Go through a tunnel on the road and continue towards the hamlet of Le Pichoux until you reach the crossroads.
(4) Follow the road to the right.
(5) Take the marked trail on the right and climb into the forest.
(6) You can make a round trip to the viewpoint overlooking the gorges and Lac Vert. Continue along the ridge through the forest until you reach the next trail junction.
(7) Continue on the marked trail and turn left until you reach the next intersection of marked trails.
(8) Take the marked trail on the right.
(9) Follow the road on the left to the hamlet of Rebevelier.
(10) Turn left and follow the road to the next junction.
(11) At the junction with an unmarked path, turn right until you reach the next junction.
(12) Take the road on the right downhill and then, shortly after, take a logging road on the left. The road turns into a path, continue downhill and find another path that turns into a logging road.
(13) At the junction between two logging tracks, take the one on the right which descends steeply. (Please note that the position of this point may be a little imprecise.) Join a path coming from the right. Continue downhill on a clear path to the bottom of the valley.
(14) At the junction at the bottom of the valley, follow the path on the right that runs alongside a stream.
(15) At the childhood home, take the marked trail on the right and climb up alongside pastures until you reach Blanche Maison, crossing several cattle gates. After the house, descend via the marked trail until you reach a road.
(16) Turn left, following the signs, then turn right and climb up to go around the Pré de Joux.
(17) Turn right and descend to the road.
(18) Before the road, follow the signs on the left.
(19) Continue straight ahead and follow the signs through the pastures (signs on telephone poles). At the next intersection of marked trails, continue straight ahead, pass the water tower, and descend to Undervelier.
(20) Turn right towards the centre of the village. At the main crossroads in the village, turn right and follow the road to Blanches-Fontaines, going up along the Sorne river. This will take you to the car park (S/E).