The itinerary starts on the same path as its easy and intermediate variants but, from Le Crêt, you'll descend to Maubuisson, then to the Château at Quaix-en-Chartreuse.
Take your fill of drinking water in the village before climbing the Pont de Vence.
Save some breath to rejoin the blue trail at Le Fa.
There are two there-and-back variants: one to La Pinéa and another to l'Ecoutoux from the Brens pass, to enjoy a magnificent view from the top.
The calculation of the difﬁculty of each course takes into account the length, the positive vertical drop, the greatest continuous positive or negative vertical drop as well as the technicality of the terrain.
All year round.
The starting point is : from the Prairie du Col de Porte
(signpost at the start of the Charmant Som road)