The 99th Tour de France started on Saturday in Liege, Belgium.
The field includes 22 teams and 198 riders, from 31 countries including Argentina, Croatia and Kazakhstan. By the time they reach Paris on July 22, the racers will have covered nearly 2,200 miles and overcome scorching heat, wind, rain and dangerous pileups, not to mention 6,000-foot mountain peaks in the Alps and Pyrenees.
Here's a look at the stages that could determine whether Australia's Cadel Evans successfully defends his title, or if Briton Bradley Wiggins or another challenger cruises into Paris with the winner's yellow jersey.
PROLOGUE (Saturday, June 30)
The four-mile individual time trial around Liegewill is a chance for Tour favorites Wiggins and Evans to show their early form. It's also a chance for outsiders such as world champion time trialist Tony Martin, Levi Leipheimer and Robert Gesink to make their mark against rivals who aren't as well-versed in the race against the clock, known as cycling's 'Race of Truth.'
STAGE 7 (Saturday, July 7)
A 124-mile medium mountain stage from Tomblaine to La Planche des Belles Filles in the Vosges mountains of eastern France. The super-steep final climb up La Planche des Belles Filles will be one of the first big tests for the climbers. The 3.67-mile climb averages an 8.5 percent gradient, but some sections top out at a staggering 20 percent.
STAGE 11 (Thursday, July 12)
The 92-mile route takes riders over two beyond-classification Alpine peaks (Col de la Madeleine and Col de la Croix de Fer) and finishes atop the first category La Toussuire. The imposing 11.19-mile climb at 6.1 percent is remembered as the mountain where Floyd Landis bombed in the 2006 Tour de France, finishing 10 minutes behind the stage winner and losing the yellow jersey. He made up almost all the lost time in a staggering comeback the next day, but he was later stripped of the title for performance-enhancing drug use.
STAGE 16 (Wednesday, July 18)
This 122-mile stage runs from Pau to Bagneres-de-Luchon in the Pyrenees and includes two beyond-classification climbs (Col d'Aubisque and Col du Tourmalet) and two first category climbs, Col d'Aspin and Col de Peyresourde. Known as "The Circle of Death" since it was first featured in the Tour de France in 1910. The 5.9-mile, 6.7 percent Col de Peyresourde comes about 10 miles from the finish, leaving little chance for anyone dropped on the final climb to catch up.
STAGE 19 (Saturday, July 21)
An exceptionally long 33-mile individual time trial from Bonneval to Chartres. The last chance for any riders who suffered in the mountains to make up time. After three weeks of high-intensity racing, racers will have to dig deep into their last reserves of stamina, strength and concentration on the Tour's penultimate stage. Likely to be a final showdown between Wiggins and Evans for the yellow jersey.