The Cosmiques Ridge (in french Arête des Cosmiques) is one of the most classic climbs in Mont Blanc Massif. This ridge on the Aiguille du Midi need minimal approach and is easily accessible from the cable car. Give easy grade (french PD/PD+), nice views and you know why Cosmiques are so popular. This is also a good way for acclimatization for harder routes, and for a relative beginning climbers great alpine goal.

Grade: AD 4a (crux has 4c)
Length: 240-300 m. Elevation 3550 m / 3842 m
Time: 2-3 hours (half of the day with approach/descent by cable car on Aiguille du Midi. But on this route can be a big traffic)
Localization: Aiguille du Midi / Mont Blanc Massif / Chamonix (France)
Character: Ridge, traverses, slabs, couloirs
First ascent: 1911, 2 August - George and Maxwell Finched


Technical Information:

Difficulty rating: PD/PD+, 4a (4c crux)
Elevation min/max: 3550 m / 3842 m
Height difference: +300 m / -300 m
Difficulties height difference: 240 m

Arête des Cosmiques offers climbing on rock, ice, and snow. It is possible to do this route in every season. It is not difficult for climbers, but you must be prepared for mixed conditions which depend from the time of the year. You will descent to the glacier and climb up granite slabs & crack.

Area of Aiguille du Midi is known for a good place for acclimatization. Typically you take a cable car to the top (~3800 m), do some route and quickly go to Chamonix (~1000 m). That was our tactic for climbing on north face of Grandes Jorasses.

Cosmiques are very popular (especially in high season (from June to September) then be prepared for a lot of people on the ridge. A good option is to start early (first cable car). Also, be prepared if there is a strong wind.


• Crampons
• Ice axe (or two in winter)
• 60 m half rope
• Half a set of nuts (mostly cams to 0.75)
• 4 slings
• 4 quickdraws
• Abseil/belay device


From Chamonix take a cable car to the top of Aiguille du Midi (ticket up/down cost ~60 euro…) and go to the ice tunnel. Descent the steep snow ridge and traverse below the South Face of the Midi (outstanding summer climbing in orange granite). Go near of the Simond Hut.


Descending from Aiguille du Midi

The Cosmiques Ridge

The Ridge start on easy mixed terrain, which leads to a small summit. At this part of the climb, you will go on the right side of the “ridge”. Take direction to the first gendarme (~3731 m ), climb the inclined slabs (4b). Go on the ridge to the second subsidiary summit. Do a descending traverse (or abseil).


View to crux of the route

Next, go to the first tower and abseil 30 m (bolted belays). Move on the right on the base of the first tower. Climb a small chimney (4a) and go up to ridge (here go also the Cosmiques Couloir). On big ledge go right around the second tower.


Author on crux pitch. Photo Tomasz Klimczak

Before you are crux section. 5 meters of terrain 4c (slab with cracks). The slab is quite easy because you have drilled (sic!) holes for your front points of crampons. Traverse right above the slab, go to the narrow ledge. From there go to the big terrace and cross the ridge to NW face.


Outstanding view!

Descent and go right to couloir chimney (2 pitches 3c and 4a).


On the ridge go to the metal ladder and access to the terrace of Midi station and to cable car, back to Chamonix.