Park in the car park of Marnans Town Hall.
(S/E) Return to the D156c road to the north. You will cross the Lolagne bridge.
You will see a signpost (Marnans - 464m). Turn left towards Viriville.
100m further on, the yellow markings indicate that you should turn right. Follow them along a grassy path that climbs steeply up the hillside. When it turns left, ignore the path coming from the right.
(1) When you reach the top of the hill, you will see a sign (Les Bonnettes - 533m). Turn right towards Combe Bajat. The stone path becomes asphalted when you cross the municipal boundary. You will arrive at the hamlet of Gros Jean.
(2) At the fork, take the right-hand branch. Then, at the next crossroads, go straight ahead. Ignore the "no exit" sign and take the "Grand Champ" path opposite. A little further on, before a garden, be careful not to miss the path that branches off to the left. Otherwise, you will end up in a farmyard (the owners are lovely, but still...). The path goes around the garden and then passes by the gable end of the farm.
Twice, at a fork, take the right-hand branch. Then you will find the yellow markings indicating that you should take a path that climbs to the left. Follow it. Further on, ignore a path that climbs to the left. At a T-junction, turn left (the yellow markings confirm your choice, even if they are not very visible). Before you reach a small pond, turn right.
(3) You will arrive at a charming little pond with no name. Stay on the same bank and walk along it. Take the time to explore this spot at the "end of the world".
From this point onwards, and for some time, your path will be quite tumultuous: it goes up, down and around... Keep an eye on the yellow markings.
(4) You will cross a small wooden bridge, which will prevent you from getting your feet wet. Further on, turn right (markers).
(5) Then a second wooden bridge (Duteil must have passed this way...).
(6) Then a third. Shortly afterwards, the path levels out, you arrive at a sort of plateau and the path is relatively straight. Follow it, ignoring anything coming from the right or left, until you reach the sign for "Come des Mermes - 612m".
(7) Turn right to arrive immediately at the dam of the Étang Communal des Mermes. If you want to go around it, turn left, otherwise go straight ahead. Whichever you choose, you will find yourself at the communal pond hut at the end of the dam.
Continue along the path, which quickly leads to a small asphalt road that you take on the right. Walk for a while before the road starts to descend steeply and turn left.
(8) Shortly afterwards, take a path on the left. It is not very visible, but in season you will find it among the nettles... It is very short. You will come out onto a small tarmac road. Cross it and take a beautiful grassy path which descends very steeply in places. At the end, it runs alongside the Lolagne and takes you back to Marnans church, next to your starting car park (S/E).