iFrom Briançon: about 20 km at 5.7%; from the south, about 15.9 km at 6.9% after the Guil valley approach; summit 2,361 m Come for the Casse Déserte, a barren slope of rock pinnacles and scree near the top that looks like nowhere else in the Alps. The Tour first climbed the Izoard in 1922, and a…