In reply to mypyrex:
The spa in Pre Saint Didier, through the tunnel and just past Courmayeur, is pretty damn good, but the buffet is crap - it's all biscuits and yoghurt and wheatgrass juice. For the entry fee, I'd expect at least some charcuterie or sliced exotic fruits, but no, they give you a paper bowl of muesli.
There are lots of castles from various ages up and down the Aosta valley, and the Roman architecture in Aosta is incredible if you are into that. There are also various other bits of Roman builds dotted around the place, in both France and Switzerland.
A short walk (if you walk, it's a long walk if you don't) from the Emosson Dam, twenty minutes drive from Cham, drops you at some fossilised dinosaur footprints, which are absolutely mind-blowing if that kind of thing blows your mind. You can even see the ripples in the sand on the beach that they were walking along. It's ridiculous, yo.