From the EDF reservoirs at Saint-Césaire to the Ponadieu Arch

Reach the start of the route via the narrow Chemin des Bassins de Saint-Césaire. Park by the EDF barrier, where there are two or three possible parking spaces. If these are taken, you’ll need to turn round and park in the wider sections of the route.

(S/E) Take the uphill track suitable for vehicles to reach the EDF buildings.

(1) Take the narrow, unmarked path leading down to the left to walk along the bottom of the reservoirs. Keep as close to the wall as possible.

(2) Cross the spillway with care, then head back up the path on the right – without climbing onto the retaining wall – until you rejoin the GR® 510, marked in red and white.

(3) Follow the GR® easily as it winds up and down. Reach the natural climbing walls, then continue along the switchbacks to reach a level path.

(4) Walk along the flat, narrow GR® path through the Bois des Malines for about 1,500 metres.

(5) Leave the (return) path on your left. Pass over the water intake and reach a small bridge without a parapet

(6) Cross the bridge and keep to the right to reach the Vallon Rousset junction (marker 77).

(7) Go under the track bridge and continue straight ahead through the Bois de Rousset until you reach another junction (marker 78).

(8) Turn left, still following the GR®, pass marker 79 and head down the path alongside the underground pipe at marker 80.

(9) Cross the Vallon de la Combe stream. Head back up the steep path to reach a junction of tracks.

(10) At marker 80, leave the GR® and take a yellow-marked path to the left. This will take you to the Arche de Ponadieu after a long descent through the forest. Take a moment to admire the scenery and the emerald reflections on the waters of the Siagne

(11) For the return journey, head back up the path you took on the way there for about 50 metres to find a track branching off to your right.

(12) Follow this (poorly) marked yellow trail back up. Due to the lack of markings, keep a close eye on your GPS app to avoid straying off the route.

(13) You’ll come to a rocky outcrop. A yellow mark on a rock indicates the direction to take. There are three slightly tricky sections to negotiate before you reach a more passable path that winds its way up to a small plateau. Follow this path, which is no longer marked

(14) At the fork in the road, turn right until you reach a wide track.

(15) Take the track that climbs to the left. At the pumping station, you’ll see a flight of steps in front of you.

(5) Climb the steps, then rejoin the^GR®, to the right, heading in the opposite direction to your outward journey.

(3) As you approach the ponds, continue along the GR® to go round them at the top this time.

(1) Then follow the tarmac track to return to the barrier and the car park (DA).

This 12.5 km route is a variation on the “From the Saint-Césaire pools to the Ponadieu arch” walk (no. 12717436). As that walk requires a car at the start and another at the finish, I’ve devised a return route using a circular route that shortens the way back.

In the warmer months, if you set off early in the morning, much of the route is in the shade.
Make sure you take enough water, as the hike has a greater cumulative elevation gain than it appears.
Make sure you have good walking boots and walking poles, as some sections of the path are quite steep.
There’s a tricky section on the way back (point (13)) with small rocky outcrops to climb over. You can avoid these sections by retracing your steps along the outward route from the Ponadieu arch (11), but the route will be several kilometres longer...

The Ponadieu Arch is an imposing rock formation naturally carved out by the River Siagne, and its name (Ponadieu) is said to mean ‘God’s Bridge’.

During the walk, you’ll come across quite a few structures built by EDF (dams, pumps, pipes, retaining walls) that form part of the Siagne power station.

The village of Mons is most clearly visible in the distance on the return journey between points (2) and (3), and on arrival.