The steep incline reaches up to 14%! From the Col de Porte, the road cuts through a forest dotted with increasingly sparse mountainous ramparts, before emerging into pastureland. You can make an initial stop at an altitude of 1,654m/5,426ft on the Plateau du Som, then continue on foot for another 30min. At the top (1,867m/6,125ft), you will enjoy a fine view over the meadows and the Grande Chartreuse convent.