From Étang des Lésines to the Planachat ridges at La Praille

From the Cluse des Hôpitaux, climb from Tenay to the Plateau d'Hauteville, at the start of which you turn right to reach Les Lésines and the car park by the lake.
You can also climb from Virieu le Grand to Cormaranche: in the village, turn left to descend to the edge of the Lésines lake.

(S/E) Take the path south along the lake. When the path hits a fence, climb up to the right to the edge of the forest and take another path, still heading south, which eventually descends to the edge of the marsh.

(1) The path crossing the marsh on stilts is clearly visible opposite. Follow it to the marsh exit near a cattle shelter.

(2) Continue climbing until you cross a small road. Take the cleared path marked "marche nordique" (Nordic walking) opposite, which climbs the hill and then turns right to go around a technical wood training area. At the junction with a road, continue climbing to the left to go around a villa and turn right to reach the cross and lime tree of Sully de Servoin.

(3) Go back and forth to the left (backwards) to the viewpoint of the statue of the Virgin Mary, then continue south on the roads that descend slightly into Cormaranche aux Platelles. Finish by turning left to climb back up towards the church.

(4) Carefully cross the Grande Rue and climb the path to the left of the church that leads up into the forest. As soon as possible, turn right to climb diagonally southwards to the meadows below the Planachat chalet.
Be careful on this section, as mountain bikes may be coming down in the opposite direction!
Climb up these meadows along the marked paths and go around the Planachat chalet along the road.

(5). Head north-east up a paved but bumpy road, shared with mountain bikes. It enters the forest and levels out. At an altitude of around 1,060 metres, take a marked path on the right that climbs more steeply towards the ridge, passes a few antennas on the left and reaches Golet Marmier.
Walk a few metres north for a view of the areas you will be covering later.

(6) Head south on the ridge trail, which descends slightly before climbing again, veering southeast to the summit of Planachat: radio tower and viewpoint with orientation table.

(7) Head east along the ridge and descend this path to the Col de la Clye.

(8) Leave the forest road that leads to the Guichard farm and climb up the steep path opposite (north) that follows the long Gigimont ridge (green markings). Shortly before its highest point, a viewpoint (bench) overlooks Hauteville.

(9) Continue along the ridge path, which eventually winds down to the Col de la Rochette road, which you follow for 50 metres to the right.

(10) Take the forest path to the north, which quickly veers left and descends in wide hairpin bends towards La Praille in a wet meadow (cross-country skiing markings).

(11) Cross this meadow towards the west and cut through part of the forest to rejoin a good path coming from La Praille.

(12) Opposite, take the downhill ski slopes, which you climb via a wide circular loop on the right to reach a path leading to the top of the slopes via the Hauteville side (orientation table).

(13) Take the ridge path (blue markings) of Haiea d'Amont to the south. When it starts to descend, do not follow the markings that turn right, but stay on the ridge path, which descends quite steeply (fixed rope at the end, which may be slippery) to a small road and the Croix du Cornillon clearing.

(14) Make a round trip to the Belvédère de Cornillon.

(15). Return to the cross, take the eastern slope, not the yellow marked path that heads south around the viewpoint to Hauteville, but the blue marked forest path that descends in wide loops to the Chapel of Notre-Dame de Mazières.

(16) After visiting the chapel, head south to join the Col de la Rochette road, which runs alongside the Ruisseau des Taillis stream until it crosses a path leading up to the Ferme Guichard farm at the entrance to a rocky gorge: the Passage de la Roche Taillée.

(17) Cross this gorge via the road and, at the "Trou de la Marmitte" sign, turn left onto the small road towards Cormaranche. You will be overlooking the Ruisseau de Mélogne stream on your right. Shortly after the junction, a first tricky path allows you to descend to the stream between two waterfalls and back.

Continue along the road for 200 metres and, opposite a quarry, you will find a path (fluorescent markings) that descends to the right towards the stream: a few log steps confirm that you are on the path, which winds down the steep slope and then crosses upstream to a high waterfall at the top of which the water flows out of a giant pothole in the cliff: the Trou de la Marmitte.

(18) Descend the stream bed, bypassing a waterfall on the left bank. The path then follows the water on the right bank to the marked path (two yellow lines) crossing the stream via a ford.

If the descent seems too difficult or slippery, you can stay on the road and, 600 m further on, turn right onto the path that leads back to the ford.

Follow this marked path on the right bank: after a slight climb, it continues with a series of descents and traverses through the forest until it joins the Hauteville road (CD8 - caution!), which you follow for 30 m to the right.

(19) Take a path on the left heading south-west downhill and cross the Maloge stream near a waterfall (downstream).

(20) Continue along the road, which becomes Chemin de la Cascade, heading south. When it turns left and descends slightly, turn right onto a path that climbs steadily towards the crest of a limestone ridge. At the top, the path flattens out: there is no need to continue straight on towards the Vierge de Servoin, which you visited on the way up (3), but instead descend to the right along a cleared track that joins the route you took on the way up. Then descend, skirting the centre of the woods, to the shelter at the entrance to the Marais de Vaux.

(2) Turn right and follow the route between the fences and then into the marsh, marked by signs with a horse's head. The route passes near pumping wells and then grassy formations in the marsh, known as touradons, before reaching the pumping station buildings.

(21) Turn left onto the access road to the station. After 300 metres, turn left to cross the meadows, go and see the outlet of the Lésines lake, then head west on the path that leads back to the car park (S/E).

Route without any particular difficulty on paths or trails, with a few short steep sections.
Only the detour to see the Trou de la Marmite (18) is steeper, with a narrow path on steep slopes (in case of slippery ground, it is possible to bypass this by turning lower down on the path).

Multiple and sometimes chaotic signage with markings or signs: marsh, footpath, mountain biking, Nordic walking, trail running, cross-country skiing, etc.

Please note that the area around Planachat is equipped for mountain biking: use the shared paths and be careful when crossing mountain bikes coming down the slopes (especially between (4) and (7)).

Views from the main lookout points over the Jura mountains and the Alps on a clear day, limited to the peaks of the Bugey on a foggy day.

The Tour du Plan d'eau des Lésines et du Marais de Vaux plunges into the heart of this natural environment, where horses have been adopted for maintenance purposes.

There is plenty to read along the route: the information panels are particularly numerous and varied, covering the marsh, of course, as well as heritage, the timber industry, and more.