Park in the large car park on the edge of the D9 road on the outskirts of Hauteville-Lompnes, in front of the last building of the ORSAC Mangini rehabilitation centre.
(S/E) Take the Black mountain bike trail, which descends through a recently deforested area, then continue into the woods.
(1) At the first fork, leave the Black mountain bike trail and turn left, going in the opposite direction to another mountain bike trail, and cross the Mélogne stream (downstream from the Trou de la Marmite, which you will discover later).
(2) About 100 metres after crossing the Mazières road, take the path that climbs to the left.
(3) After the climb, continue straight ahead on the flat path in the opposite direction to the mountain bike signs.
(4) Follow another climb to the left, then continue south.
(5) Continue straight ahead, partly following the mountain bike trails.
(6) When you reach the foot of the old Planachat slopes, turn left onto the semi-tarmaced path marked PR®.
(7) Leave the track to take the "coupe-lacet" climb and reach Golet Marnier by following the PR®.
(8) At the Golet Marnier crossroads, turn right onto the PR® towards the Belvédère de Planachat, via a ridge path that becomes steep towards the end. Pass at the foot of the huge television relay tower and reach the summit of Planachat.
(9) After admiring the view, descend via the PR® towards Col de la Clye. At the intersection, continue to the left.
(10) At Col de la Clye, follow the road (PR®) towards Ferme Guichard, pass the farm and continue for another 200 metres.
(11) Continue along the PR® trail, turning left through the woods.
(12) Ford a stream and follow it on your right before joining the RD9 (Col de la Rochette road) at the "La pierre taillée" sign.
(13) Make a return trip following the road on the left to discover the famous Trou de la Marmite. To see it properly, you have to climb down the very steep embankment beyond the tourist sign. Once you are close enough to see it, there is no need to get any closer if you are afraid of heights. Please be careful at all times.
(14) Then retrace your steps.
(13) Turn left and carefully follow the road north for 400 metres.
(15) Turn right to reach the Notre-Dame de Mazières site and discover the statue of the Virgin Mary, its legend and its chapel. Picnic tables and barbecues are available, but please respect the spirituality of the place.
(16) Set off again on a steep climb towards the Croix de Curnillon (spelled Cornillon on the map and Curnillon on the signs).
(17) Turn left to go to the Belvédère de Curnillon.
(18) Retrace your steps.
(17) Continue straight ahead and cross the crossroads to take the steep path opposite.
(19) Continue along the ridge path with one last steep climb, then a pretty trail that offers glimpses of beautiful views here and there when the vegetation allows. You will reach the second highest point of the route: the summit of La Praille.
(20) Orientation table from where you can admire Mont Blanc on a clear day. The descent is via one of the ski slopes on the west side (blue Tétras or green Dahu slope) to the road, which you follow to the left for about 250 m (avoid the black slope called "KL" on the east side, which descends steeply towards La Praille!
(21) At the crossroads, turn left onto the forest road towards Curnillon, which descends gently.
(22) Descend to the right one last time on the black mountain bike enduro trail to complete this loop and return to the car park (S/E).