Dams and forest around Planfoy

Circular hike to the Gouffre d'Enfer and Pas du Riot dams, built under Napoleon III using stone masonry.
Admire the height of the conifers growing in these forests. The nearby Col de la République, also known as Col du Grand Bois, lives up to its name.
The route is mainly through woodland and is not difficult. There is very little tarmac road (only at the start and finish).

Details

3906243
Creation:
Last update:
Last review:
  • Walking
    Activity: Walking
  • ↔
    Distance: 13.49 km
  • ◔
    Average duration: 4h 55 
  • ▲
    Difficulty: Moderate

  • ⚐
    Back to start: Yes
  • ↗
    Ascent: + 360 m
  • ↘
    Descent: - 366 m

  • ▲
    Highest point: 1,051 m
  • ▼
    Lowest point: 781 m

Photos

Description of the walk

Planfoy is located 7 km south of Saint-Étienne. Take the "Le Rond Point" exit on the RN 88. Follow signs for Annonay-Valence-Col de La République. Start from Planfoy church. Car park near the town hall, 50 m away.

(S/E) With your back to the church entrance, turn right onto Rue Georges Clemenceau. After 250 m, turn right onto Chemin de Corbières.

(1) At a fork before the last house, take the right-hand path which descends gently towards the forest. The slope becomes steeper and the path more stony. After a hairpin bend to the left, you will come to an intersection (elevation 854).

(2) Follow the path that branches off to the left at a 90° angle. Descend heading north. When you reach the lake called Gouffre d'Enfer, turn right and walk along the top of the dam. On the other side, ignore the steps leading down to the left and continue for about 50 metres.

(3) At the fork, climb left to reach the viewpoint. Retrace your steps.

(3) Turn sharply left, then veer right (south) to walk along the lake on your right and the Fontaines aqueduct on your left (watch out for mountain bikes!). At the end of the lake, gently climb up the valley.

(4) Cross the Furan via a footbridge and follow the river on your left. After two hairpin bends uphill, you will arrive at a stone structure with 10 arches and 10 sluice gates that were used to direct the flow towards the aqueduct or the Furan (information panel).

(5) Cross the Furan again and take the path that immediately branches off to the right. Cross the Ruisseau des Sagnols to reach a very wide path (recent earthworks). Follow this path to the left. Make a hairpin turn to the right, continue south and arrive at the Pas de Riot dam.

(6) Turn right and walk along the top of the dam. At the end, turn left onto a wide path and walk along the lake on your left.

(7) At the small cove of Pont de Turenne, turn right onto a faint path that climbs into the forest. Continue south then south-west, ignoring the paths coming from the right or left. The path makes a sharp right turn as it crosses the stream. The climb continues until you come out opposite the stadium and campsite.

(8) Descend along the road and turn left. Before a right-hand bend, take the small tarmac path (no entry sign) and join the D1082. Cross the road and take the path opposite, which runs alongside some sheds. Continue along the path and enter the woods. Climb up through the woods and, at the exit, continue on flat ground towards the hamlet of Corduran. Leave the hamlet on your right and turn left to reach the D1082.

(9) Follow the road to the right without crossing it. About 50 metres further on, take a path on the right between the meadows. After 500 metres, turn right and then right again to reach the hamlet of Bel Air.

(10) Leave the buildings on your left and continue along the path. At the fork that you will soon come to, take the left-hand path. Enter the woods (the Vernets peat bog is signposted on the right). You may need to stray slightly from the path, which can be muddy even in summer.

(11) Cross the road at the large crossroads at Croix de Trèves and then take the wide path that branches off to the right. When this turns right, continue straight ahead on a narrower path. Cross the forest, heading north-east.

(12) At the Le Petit Nice crossroads, turn left onto the main path, leaving the houses on your right. Enter the Bois de la Neyranche, stay on the wide marked path and ignore all the paths branching off to the sides. 50 metres after a building on your right and 50 metres before a cross, you will find a hairpin path on your right that leads downhill.

(13) Follow this path, which crosses a stream and becomes Chemin du Moulin, which quickly leads to the D1082.

(14) Cross carefully (heavy traffic at certain times) to take Rue du 19 Mars 1962 opposite, which leads back to the church (S/E).

Waypoints

  1. S/E : km 0 - alt. 946 m - Église Saint-Étienne (Planfoy)
  2. 1 : km 0.38 - alt. 932 m - Fork
  3. 2 : km 0.8 - alt. 856 m - Intersection
  4. 3 : km 1.72 - alt. 788 m - Access to the viewpoint
  5. 4 : km 3.52 - alt. 797 m - Footbridge over the - Furan (rivière)
  6. 5 : km 4.01 - alt. 825 m - Stone arches and sluice gates
  7. 6 : km 4.82 - alt. 854 m - Pas de Riot dam
  8. 7 : km 5.47 - alt. 854 m - Turenne Bridge
  9. 8 : km 7.2 - alt. 1,019 m - Stadium and campsite.
  10. 9 : km 8.8 - alt. 1,039 m - D1082 road
  11. 10 : km 9.5 - alt. 1,043 m - Bel Air
  12. 11 : km 10.78 - alt. 1,040 m - Croix de Trèves
  13. 12 : km 11.54 - alt. 997 m - Le Petit Nice
  14. 13 : km 12.55 - alt. 969 m - La Neyranche
  15. 14 : km 13.2 - alt. 939 m - D1082 road
  16. S/E : km 13.49 - alt. 946 m - Église Saint-Étienne (Planfoy)

Notes

Easy route. Standard hiking equipment.

The woods between (10) and (11) can be muddy.

The first section (dams) can be very busy at weekends and during holidays.
Picnic tables at point (8).

If you have difficulty parking in Planfoy, you can start the hike by parking at the point (11), the "Croix de Trèves" crossroads, which can be reached by taking the D501 towards St Genest Malifaux.
Restaurant in Planfoy. Public toilets in the car park below the Town Hall.

Worth a visit

Via Ferrata at the first dam.

Nearby, there is the Roche Corbière climbing rock with numerous routes equipped for all levels.

The dams on the Furan were built a few years apart under Napoleon III. The Gouffre d'Enfer dam was one of the first stone masonry gravity dams in the world, designed to supply drinking water to the city of Saint-Étienne and hydraulic energy to its factories. Access to the foot of this dam is possible via the staircase on the right bank.

Major civil engineering works have recently been carried out on the Pas de Riot dam. The downstream masonry has disappeared under thousands of cubic metres of embankments, and a new spillway has been created. The zigzag path shown on the IGN map, which used to lead down to the foot of the dam, has disappeared as a result of the work. The Gouffre d'Enfer dam is now only used as a reservoir for floodwater and its level is generally at its lowest. Access to the foot of this dam is possible via the steps on the right bank.

Tourbière des Vernels between (9) and (10).

At the end of the hike, walk 4 km to Sacré Cœur du Guizay by taking the road at point 13. Orientation table with a magnificent view of St Etienne (Grande Rue de Saint-Étienne in the axis), the Loire Valley and the Monts du Forez... and even... "le Chaudron" des Verts in the background, slightly to the right! .

Reviews and comments

4.7 / 5
Based on 11 reviews

Reliability of the description
4.8 / 5
Ease of following the route
4.8 / 5
Route interest
4.6 / 5
jamarnaud
jamarnaud

Overall rating : 5 / 5

Date of your route : Apr 21, 2026
Reliability of the description : Not used / Not applicable
Ease of following the route : ★★★★★ Very good
Route interest : ★★★★★ Very good
Very busy route : No

A hike done in April 2026 with GPS tracking, so in spring; a lovely start towards the Gouffre d'Enfer and then some beautiful stretches through the woods. It must be lovely in summer.
In April, a few muddy sections but manageable.
Quite a few people around the Gouffre d'Enfer, which is the end of the via ferrata.

Machine-translated

4feet69
4feet69

Thank you for pointing out the discovery routes that did not exist when this route was created five years ago. That's why it's important to read the comments.

Machine-translated

User 19948365
• Edited:

Overall rating : 4.7 / 5

Date of your route : Oct 20, 2025
Reliability of the description : ★★★★★ Very good
Ease of following the route : ★★★★★ Very good
Route interest : ★★★★☆ Good
Very busy route : No

Well-detailed route. The points of interest are a pleasant route often through the forest. With views of Planfoy, the wetland biotope with two small discovery trails included on the route. The first passes over the Pas du Riot dam on the left, indicated just to the right of the small dam house just at the exit. (Not indicated on the trail, which takes you to the right of the dam). The second is about three-quarters of the way along, indicated by signs on the trail. This circular route is not difficult, with only a few small, easy climbs.
It is busier on the Gouffre d'Enfer section. For a successful day, I recommend arriving at 9:00 a.m. and renting via ferrata equipment (for children and adults) at the bar in the village of Planfoy. Enjoy this magnificent and accessible via ferrata (for via enthusiasts) and then take the hiking trail when you exit the via. Have a great walk!

Machine-translated

Elizabeth
Elizabeth

Overall rating : 5 / 5

Date of your route : Sep 25, 2024
Reliability of the description : ★★★★★ Very good
Ease of following the route : Not used / Not applicable
Route interest : ★★★★★ Very good
Very busy route : No

• Beautiful hike with very varied landscapes.
• Please note: a diversion prevents you from continuing to the Pas du Riot along the Suran river due to major construction work. However, everything is very well signposted. The diversion takes you along a parallel path, which is slightly higher up. On the map, it is the black path that leads to Les Sagnols, so it is not a problem at all.

Machine-translated

Yann Frmtx
Yann Frmtx

Overall rating : 4 / 5

Date of your route : Mar 24, 2024
Reliability of the description : Not used / Not applicable
Ease of following the route : ★★★★☆ Good
Route interest : ★★★★☆ Good
Very busy route : Yes

Great hike, but not very interesting between points 7 and 8, which are uphill and the path is rocky and muddy when it rains. At point 11, I extended the hike to Croix de Pauzou and then on to point 13, making it a total of 19 km. I completed the hike in 3 hours and 10 minutes at a steady pace (about 6 km/h).

Machine-translated

Bessenay21
Bessenay21
• Edited:

Overall rating : 4.7 / 5

Date of your route : Oct 08, 2023
Reliability of the description : ★★★★☆ Good
Ease of following the route : ★★★★★ Very good
Route interest : ★★★★★ Very good
Very busy route : Yes

An interesting and varied route in terms of scenery. It is very busy in the first half (close to the dams on a Sunday), but very quiet once you climb up into the forest. We loved it!

Machine-translated

4feet69
4feet69

Guillaume's suggestion is a good one; it will lengthen the route slightly but without any additional elevation gain.

Machine-translated

guy pagat
guy pagat

Overall rating : 4.7 / 5

Date of your route : Aug 07, 2022
Reliability of the description : ★★★★★ Very good
Ease of following the route : ★★★★★ Very good
Route interest : ★★★★☆ Good
Very busy route : No

A lovely walk under the trees, ending in the charming village of Planfoy.

Machine-translated

Guillaume_42_1991
Guillaume_42_1991

Overall rating : 4.7 / 5

Date of your route : Jun 25, 2022
Reliability of the description : ★★★★☆ Good
Ease of following the route : ★★★★★ Very good
Route interest : ★★★★★ Very good
Very busy route : No

A beautiful, uncrowded hiking route, with lovely views. At the Pas de Riot dam, you can also walk up the right bank to the bridge, cross the Furan river to go around the lake before tackling the climb.

Machine-translated

Pipit42
Pipit42

Overall rating : 5 / 5

Date of your route : Oct 17, 2021
Reliability of the description : ★★★★★ Very good
Ease of following the route : ★★★★★ Very good
Route interest : ★★★★★ Very good
Very busy route : No

A very pleasant hike with only one notable difficulty.
The paths are very pleasant and the route markings are perfect.

Machine-translated

grandin
grandin ★

4feet69

Thank you for your follow-up.

Machine-translated

4feet69
4feet69

Description and itinerary modified to take into account your observation regarding the private road.

Machine-translated

grandin
grandin ★

Gèoportail indicates that this path is indeed private.

4feet69, can you modify the route accordingly?

Machine-translated

4feet69
4feet69

Admittedly, there is a "private road" sign; we are all familiar with these signs put up by residents or farmers who do not like to see hikers walking along their property. It would be advisable to consult the land registry to be sure.

Machine-translated

michel1941
michel1941
• Edited:

A beautiful hike that I recommend to everyone, but be careful at point 13: the path is private. Before the hamlet, take a marked path towards an iron cross that will lead you to the church in Planfoy, the starting point of the hike (7 km). The Gouffre d'Enfer cave is dry, but there is a magnificent view from the first dam. Thank you to the organiser.

Machine-translated

Other walks in the area

For more walks, use our search engine .

The GPS track and description are the property of this route's author. Please do not copy them without permission.