Access: from Geneva, take the A40 motorway, exit at Saint-Julien-en-Genevois, then follow the D1201 towards Cruseilles (or from Pas de l'Echelle, take the N206 (D1206), then turn left onto the D18 (Archamps) until you reach the N201); shortly before the Col du Mont Sion, at the roundabout, head up to Pomier and then to the car park (Mikerne) at the Maison du Salève (former Carthusian barn)
(S/E) From the car park, at an altitude of 760 m (you can already see the harbour of Geneva; there is a beautiful view of Pomier Abbey), take the path that climbs and runs alongside a stream (signposted, start of the educational trail; the stream was dug by the Carthusians to supply a mill).
(1) You will come to a crossroads; continue to the left (Les Hauts de Mikerne, 810m, signposted "Les Convers"), then straight on to "Pomier" where you take the path that climbs to the right and passes in front of a stable. You will enter the forest, pass in front of "Le Rocher à Roger" and continue to the left, "Sentier des Petites Croix" (Les Convers on your right will be for the return journey).
(3) Shortly afterwards, turn right, following the signs for "sentier des Petites Croix" and the red and white cross markings on the tree trunks; the climb becomes steeper in a beautiful beech forest. Keep following the distinctive markings. The trail climbs over a few rocky outcrops before running along a wall on the left. Go around a fault corridor on the right before reaching the Saint Bruno oratory (a pretty promontory with views of the Mont Sion pass, the plain on the Pays de Gex side and the Jura).
(4) Continue through a small valley until you reach the Convers signpost, which you leave on your right to climb to the left, still on the Petites Croix trail. After a few hairpin bends, the forest becomes sparser; the slope levels out and you walk along a rock face (rock climbing school). You pass close to a small clearing on the plain before returning to the spruce trees and a short climb up a fairly steep slope, first through rocky outcrops, then through a forest that could be described as "devastated": uprooted, cut down and diseased trees (probably bark beetle), scattered stumps... in short, a strange atmosphere. You reach the edge of a cliff overlooking a small gorge (with a beautiful view of Geneva and its harbour in particular) and the path continues at a right angle; you come out onto pastures at around 1120m (if you turn left, you will arrive at La Thuile).
(5) Turn right and follow the path along the edge of the forest; after a short descent, you will reach the bottom of a small valley; turn right and climb up into the forest, following the fence. As soon as possible, cross the fence (carefully); after a short descent, you will come to a path which you follow to the right, crossing a stream. Shortly afterwards, you will reach the Chalet des Convers, at 1200m. Nice view of the plain and the Jura. I didn't have enough time, but you can easily reach "Plan du Salève" (or Pointe du Plan), at 1348m, for a clearer view of Mont Blanc and Annecy.
(6) To descend, head west, following the signs for "Maison du Salève par Pomier". Cross the pasture (signs at the edge of the forest), enter the woods where you will find the path; you will pass a chalet before beginning the descent. The path is a little less steep than Les Petites Croix. Descend via the switchbacks (follow the signs carefully; don't do what I did and head straight down the slope to find the right path).
A little further down, near the Pomier rocks, you will pass the start of the Jacques Revaclier Via Ferrata (free access).
(2) The end of the route is a gentle slope (yellow markings) until you reach the fork in the path and, shortly after, Pomier. From there, you can head straight across the fields to the car park. (S/E)
