Start at Rochasson Castle (in the town of Meylan).
(S/F) Follow the direction of Bois d'Avril.
(1) Turn left uphill. At the crossroads of Bois d'Avril, turn right towards the Corbeau Castle. Then pass overs a first stream.
Arrive at a rustically furnished space (wooden fences), where there is a flaming fountain on your right (2).
Take the road towards Corbeau Castle. Do not cross the bed of a second stream but follow the hillside on the right. Continue along this hillside, cross the first stream, then start your descent.
Find the path from the way in and then continue down to Rochasson Castle and return to starting point (S/F).
This route is very slippery and should be avoided in wet weather. Walking sticks are a necessity. There is also a chance of rocks falling.
In the nearby area
(2) Fontaine Ardente: at the flaming fountain, you can smell the sulphur. In a recess in the wall, depending on the season, you can see glowing embers or a small spark.
To open this route on your smartphone, you must have the Visorando app installed. If not, got to the Apple Store (iPhone) or Google Play Store (Android) to download the app.