The turning to the Col de la Croix de Fer is a few kilometres west of Alpe d'Huez along a wide, flat road. The southwestern ascent of the Col de la Croix de Fer is a sleeping giant of a climb. It doesn't have much in the way of sexy hairpins, crumbling rockfaces or jaw-dropping canyons, but it doesn't disappoint.
There has been a route up over this mountain pass since time began. Much of the road remains the same compared to the old days. The only difference now is two reservoirs, one at the top and another at the bottom. They regulate the colossal snowmelt coming off the mountain tops every spring.
The total distance is 32km, and the average gradient is only 4.1%, but the figures are deceptive. Within the climb are sections of 11%, and towards the top, the air is noticeably thin. But you won't mind because by then, you will be riding up across the roof of the world.