Start at Chemin de Carron. At the hamlet of Trucherelle, turn left towards Le Poyet and follow the road for about 200 m. The start of the walk is just beyond the end of the tarmac section, at a point where the road crosses a stream that is often dry. Two forest tracks branch off on either side of the stream. Park along the road.
(S/E) Take the track on the right, on the left bank of the stream.
(1) The track soon branches off to the left, whilst a path (not shown on the IGN map) continues straight ahead. Stay on the track. Shortly after this bend, carry on straight ahead at the junction with another forest track that branches off to the right.
(2) When the main track veers to the left, turn right. The track soon opens out onto a small path: take this to the left (marked with a blue sign, which is rather faded in places). The path joins the Eyrard stream: follow the stream upstream until you reach the foot of the first waterfall (the path is not always clearly marked at this point).
(3) Climb to the right of the waterfall along a very steep and poorly marked path right at the foot of the rock face. You’ll soon reach the rocky passage known as the Pas de l’Eyrard, which a cable and steps carved into the rock help you to cross. At the end of this section, continue climbing alongside the stream (a faintly marked path still exists) until you reach the foot of the second Eyrard waterfall, where you’ll come across a clearly visible path (Chemin de Fontrasset).
(4) Take this path to the left to cross the stream and continue through the forest, at the top of the cliff. After a while, the path joins a wide forest track at a hairpin bend.
(5) Do not take the track but turn left onto a small path, marked by a cairn, which descends steeply. This path reaches an electricity pylon: ignore a track branching off to the right at this point and continue downhill until you come out onto the Carron track.
Follow this track to the left to return to the starting point (S/E).