Guidebook with maps/step-by-step :
0/ From the Chailles bridge spanning the Doron (stream), take the track that winds its way up through the forest.

1/ After the 3rd bend, take a path on the left (sign). It crosses a brook and then joins another path above (coming from Champagny le Haut - sign "Combe de Verdon"): turn right; after a 150m-ascent, you arrive in the meadows of the Enclos du Seil.

2/ Keep going to the left, at the junction. The path rises a little.

3/ At the next junction, turn right and go up for 100 meters to reach a small "pass" near the top of the Merle tower!
Caution, the ascent of the tower is dangerous (crumbly rock).