One of the oldest sportives in the cycling calendar and still the ultimate cycling test. The route takes in some of the most famous climbs from the Tour de France including the challenging Glandon / Croix de Fer, the highest point in the race on the Galibier and then the famous switchbacks of Alpe d'Huez.
This is both a long sportive at 174km and one with an enormous amount of climbing at over 5,000m. On top of this, it is in July in the Alps so temperatures could be uncomfortably hot and you go over high at the Galibier so the chance of very changeable weather is strong. There are not many tougher single day sportives in the world.