A grainy old shot of one of the boulder problems i...
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.