To climb Mont Blanc using the Cosmique route, take the cable car to the Aiguille du Midi (3,842m).
From here, descend the Aiguille du Midi arête to the glacier du Tacul, where there is approximately 1 hour walk on easy terrain to the Cosmique Refuge (3,613m). Early on the day after, start climbing the Mont Blanc du Tacul.
This ascent can be difficult at times. Due to warm temperatures, in recent years more crevasses have opened up and, at times, this has required climbing on some steep exposed terrain.
After reaching the shoulder of Mont Blanc du Tacul descend and traverse the Col du Mont Maudit. From here, ascend a long snow slope to the final piece of technical ground, which can be very steep and requires good front pointing technique and use of an ice axe. Watch out for a bottleneck of mountaineers here!
Descend once again to Col de la Brenva, with stunning scenery towards Italy, then climb the last few hundred metres to the summit.
Although relatively easy, this is generally quite slow due to the effects of altitude. This route takes approximately 6h to the summit. Descend the same way or via the Gouter, completing the traverse of Mont Blanc.
This is a slightly more demanding route than the Gouter route, both technically and physically. Tackle steeper ground and there are a couple of traverses that may be icy and difficult. Good crampon and ice axe technique are essential. It is, however, a more interesting route with beautiful scenery and is less crowded.
The Cosmique Refuge can also mean a better night’s sleep, and can be less busy than the Gouter Refuge. This is a route which is long and sustained, less popular than the classic route, but which traverses the roof of Europe.
The ideal period is from March to September (depending on conditions) 5 – 8 hours of ascent, 3 – 4 hours of descent. 1,300m of ascent, 3,800m of descent.