A grainy old shot of one of the boulder problems i...
This valley is within Parc National Ecrins
The valley Ailefroide (literally "cold wing") is just within the park boundary to the southeast. It is a wide, triangular, post-glacial valley with a meadowed and forested floor bounded by a couple of streams running through. The road into the valley terminates at a trailhead about 2 km up from the valley, so this is the departure point for accessing the major glaciers of the Ecrins Massif (another entry perhaps).
The valley is walled by the very tall but somewhat discontinuous granite buttresses of the peaks beyond. Thus the climbing is generally multipitch slab/face along with some single pitch on some of the lower tiers. The routes are "equipe". Bolt anchors, bolts at the harder sections of climbing, and established rap lines. The guidebook indicates where this varies.
The open part of the valley is about 1 square km. Most of this area is part of the campground.
The valley is a ski resort in winter. Within walking distance from the camping(maybe a km at the most)there is a tabac for provisions, a restaurant/bar, & gear shop, but they don't open until late junish-mid july. Other than these places there is really no other indoor refuge and weather here hits hard, sometimes for days on end, though apparently it's supposed to be a fair weather spot in the southern alps. Also apparently it gets very crowded mid summer.
The best source of detailed climbing info would be local sources. Some local people have taken the effort to put great info online (in English!) as well. There is nice bouldering here too. Arguably this spot is total world-class beauty.
I spent a week or two here several years ago and bouldered a bit. In retrospect, I wish I'd explored the longer routes while I was there. In any case the bouldering in Ailefroide is really nice: the rock is really good granite, the lines are aesthetic, and the scenery is amazing. It's a good place to go without a guide and just explore.
I've spent my first 17 summers making amazing memories in that Valley and the ones surrounding it. Amazed to see a page about Ailefroide on mountain project!
The main campground is really big and people are extremely friendly all around. Lots of the campers come for hiking the hundreds of wonderful nearby trails, and some for more challenging mountaineering. However the climbing community is very present: - world class bouldering events (Tout à Bloc!) & climbing/mountaineering film projections - very helpful guides have an open office on the main / only road, where you'll find everyday weather condition and forecast, and many more informations
Like mentioned in the description there is a HUGE amount of climbing: - Boulder fields worth exploring, some along the way up the 2km road going to the bottom of the glaciers trails - Multiple areas of fantastic granite (you literraly are surrounded by mountains and "spot the climbers" is a common lunch game) for every level, - but also Limestone and various formations of same high quality closeby (from 15 to 45min driving)!!
The season starts in April-Mai and ends around October, and like many places in the south of the Alps it gets great sunny days but stays cold at night. Can get stormy up to a few days in a row (mostly in August). I recommend going there in June, best temps, nature blooming and lot less people than at the peak season (mid july - mid august)
Also the gear shop and grocerie store are open earlier in the year than described. And there is no skiing in Ailefroide in the winter, the road up is actually closed when it starts snowing.
Extra infos: - other smaller campgrounds exist along the main road after the torrent, some are taken by kids summer camps, some by climbers - the last 5km of road up between Pelvoux (last city down the valley; closer than Valouise actually) and Ailefroide was completly redone in '05, way safer (wider and flat) and perfect for freebording - I very highly recommend to eat at Engilberge Restaurant-Hotel at least once in your life, landmark of the small town since 1896, awesome family business and absolutely the best food I have ever had the chance to eat!
Enjoy Ailefroide and be aware of the Ecrin National Park guidelines to preserve those awesome areas!