Dusseldorf - Ahead of the start of the 104th edition of the Tour de France in Dusseldorf on Saturday, we look at five key stages in the three-week race:
160.5km from Vittel to La Planche des Belles Filles
In terms of time gaps, this will not be the most significant or telling stage, but what it will do is have an impact on morale and confidence. It is the first real chance for the overall contenders to test their legs and there will be time gaps -- albeit likely small ones -- between the favourites. Chris Froome won here in 2012 before finishing second to team-mate Bradley Wiggins in the Tour that year. Vincenzo Nibali also won the stage here in 2014 when he dominated the Tour. The final climb is steep but only 6km long and will give an early indicator of who has good climbing legs and who will struggle.
181.5km from Nantua to Chambery
The first high mountain stage finishing in the Alps includes three hors category climbs and another four categorised ones as well. It has the three steepest climbs on the Tour this year: Col de la Biche, Grand Colombier and Mont du Chat, averaging gradients between 9 and 10 percent. This is a stage that will weed out the potential contenders who simply aren't up to the task as the risk of losing serious time is huge. Anyone struggling on this stage will see their overall hopes go up in smoke. The Mont du Chat featured in June's Criterium du Dauphine where the strongest riders distanced their rivals. Denmark's Jakob Fuglsang won the that stage and went on to win the Dauphine, establishing himself as a Tour contender.
214.5km from Pau to Peyragudes
This could be the key stage of the whole race as the final 42km are extremely tough, including around 25km of Pyrenean climbing. The final kick up to the line at Peyragudes is particularly steep with sections including a 16 percent gradient in the final kilometre. Fireworks can be expected on this one of only two high mountain summit finishes. Alejandro Valverde soloed to victory here in 2012 although Froome might have caught him but for having to wait for his Sky team leader Wiggins.
179.5km from Briancon to Izoard
The previous day's return to the Alps is probably a tougher stage with the Col de Croix de Fer, Telegraphe and Galibier climbs on the menu. But this one ends on the summit of the Izoard, a brutal climb of 14.1km at an average 7.3 percent gradient. Riders will also be tired by now and this will be the pure climbers' last chance to gain time or make a decisive move. The Izoard may be making its debut as a stage finish but it is a well known Tour climb and even includes a cycling museum at its summit and a memorial honouring Tour greats Fausto Coppi and Louison Bobet.
22.5km time-trial around Marseille
The penultimate stage is essentially the one in which the Tour winner is decided. Whoever emerges from the Stade Velodrome home of Marseille's Ligue 1 football team -- where the stage both starts and finishes -- wearing yellow will have won the Tour. It's not the longest of time-trials but if time gaps are close following the mountains, this will give a good time-trialler the chance to overhaul a more specialist climber. It promises to be a thrilling finale. In 2012 Wiggins cemented his Tour victory with a dominant victory over Froome in a penultimate stage time-trial.