Aiguille du Midi - South Face & Eperon des Cosmiques


symbol key

1 day

Maximum Ratio
2 climbers per guide

Guiding Fees

Booking info

Google Earth 

Alps Advice

The well-known French guide Gaston Rébuffat must have really linked this, sunny side of the Aiguille du Midi. He was the climber who opened up both of these now popular and classic alpine rock climbs. He first climbed the South Face of the Aiguille du Midi on July 13, 1956, and Eperon des Cosmiques one month later on the 13th of August.

These routes became well-known and quite popular very quickly. For many, ourselves included, perhaps the most enjoyable kind of climbing is found on sun-warmed rock, high about wild crevassed glaciers. The rock on these climbs is excellent golden granite, rough and textured, but monolithic with big slabs cut by long cracks.

These are day climbs, easily done from a base in Chamonix by taking an early cable car. However, the nearby Cosmiques hut allows climbers to stay up high, and do any number of great day climbs at a more relaxed pace from a hut base.

The Rébuffat route is the most classic of the many routes on the South Face. It is moderately long, about 10 pitches, with many in the 5.8 to 5.9 range. The crux section is mid-5.10, but short. Most climbers aid their way through this steep bulge. Higher, the "S" crack gives continuous 5.9 climbing with a thin crack splitting an immense slab. There are many strategies that climbers adopt to do this route. The more ambitious will climb from the bottom of the route, carrying their boots, crampons and packs from bottom to top. Others, more conservative, will leave packs at the base and descend the route by rappel. And other, bolder, climbers will start at the top, rappel the route, then climb back up to the summit and the cable car back to town.

The Eperon is somewhat shorter and easier than the South Face. But even it has some hard climbing, particularly at the steep roof at one-third height (usually climbed wit the aid of fixed gear, conveniently placed for the hands at the crux). The route is perhaps about 6 pitches in length, and finishes on a small summit-spur ridge of the Arête des Cosmiques. Most climbers will leave boots and packs at the base, then rappel the route (or actually a nearby line) to retrieve their gear. However, it is also possible to carry boots and packs up the route, and finish the climb of the Midi via the Arête des Cosmiques. After a couple easier pitches at the start, a steep pitch leads up to and over a roof to a good stance above. The roof is about 5.10c-d if climbed free, but a few aid points bring this down to an easier rating of about 5.8. Above, two more steep 5.8-9 pitches leads to easier climbing just below the small summit.

On the Rébuffat Route of the South Face of the Aiguille du Midi
photo info

Climbing on the Eperon des Cosmiques


Both of these routes are technical rock climbs. They are not particularly long, with the Eperon taking perhaps 3-4 hours and the Rébuffat route maybe 5-6 hours. Access if very easy and quick from the cable car. The difficulty lies in the technical nature of the climbing.


Climbers should have well-developed rock climbing skills and be comfortable following 5.9 rock. Experience on multi-pitch routes and on long rappels is necessary.


The Cosmiques hut is the base for many many routes of every style and difficulty. Climbers could happily spend many weeks in this area alone. Other good rock routes of a similar style and difficulty in the area include the many routes on the SE face of Pointe Lachenal, routes on the Trident or Pic Adophe Rey, or the NE Buttress of the Tour Ronde.

The Cosmiques hut
photo info

The Aiguille du Midi
photo info

Kathy Cosley & Mark Houston
UIAGM Internationally Licensed Mountain Guides

AMGA Certified • SNGM members
information about the logos

All images, layout and text ©2004 Cosley & Houston Alpine Guides, All Rights Reserved

Your Comments - more info