Direction of travel: counter-clockwise.
Landmarks and connections: Armoy (separation with Circuit de Planbois n°50); Vailly (separation with Tour du mont d'Hermone n°29 and Circuit de la Vallée verte n°28); Mégevette; Sommand / Praz de Lys; la Côte-d'Arbroz.

Description: Formerly known as the Mont Maudit, the Roc d'Enfer deserves its name both because of the storms it attracts and because of its slippery, stony escarpments where accidents are frequent. No such risk for cyclists, who need only fear fatigue, particularly on the ascent of the Col de la Ramaz. If you're feeling fit, you can take a short detour just before the Col de Jambaz. Staying on the RD26 (followed from Thonon), go back and forth to see the Lac du Vallon à la Chevrerie. This was formed by an ancient landslide that held back water from the Brevon torrent. At Mégevette, turn left off the RD26 onto the RD226 to chez Besson (Mieussy), then up to Sommand and the Col de la Ramaz via the RD308. After crossing Praz de Lys, take care on the descent: after 5 hairpin bends, turn left onto the Col de l'Encrenaz road (RD328). Similarly, after Côte d'Arbroz, take a hairpin bend to the left to pass through Essert-Romand. Return to Thonon on the RD902.

Admission fee : Free access.

Opening : From 15/05 to 31/10.

Area : Praz de Lys