The valley from Modane up to the Col de Chaviere was the sight of action during WW II. There are many shell casings visible and the landscape is pockmarked with depressions from explosions. Note shell casing lying on the ground below.
As we ascended, the temperature got colder, the wind got stronger, there was more and more snow - and we were much higher, up to about 2800 meters. Alan at the top of the col points the way down the valley on the other side.