Most of the talk amongst observers and fans surrounding this year's Tour de France has focused on the penultimate stage that takes riders up Mont Ventoux. Nevertheless, there's an equally daunting day preceding the peloton's romp up the feared slopes of the 'Giant of Provence'.
The 17th stage of this year's race, a 169.5km journey from Bourg Saint Maurice to Le Grand Bornand, may weed out the final five or six riders who will be in contention for the overall win ahead of the final time trial and the Ventoux challenge.
A parcours that boasts four first category climbs - the Cormet de Roselend, Col des Saisies, Col de Romme and Col de La Colombière, plus a second category toughie, the Col d'Araches - stage 17 is tailor-made to soften the riders' legs and wills with several days of racing remaining.
"One bad moment or misjudgment by a top GC rider, and it's all over." - Jonathan Vaughters on stage 17
Current race leader Alberto Contador (Astana) has called this day the "queen stage" of the Alps, saying it "may be more decisive" than the summit finish in Verbier, Switzerland, where he took the yellow jersey on Sunday. The Spaniard expects plenty of attacks, especially on the last two climbs, the Col de Romme and Col de La Colombière, which "feel as if they are one great ascent, as there is virtually no recovery between the two."
Garmin-Slipstream team manager Jonathan Vaughters said of the stage: "This is a rough, rough day in the Alps without any single decisive climb, but plenty of hills. It's a day that will require you to be on the ball all day long. One bad moment or misjudgment by a top GC rider, and it's all over."
In previous editions it has been all over for some notable riders on the slopes of these climbs, whilst others have excelled on them and gone on to win the stage. Let's take a look at pivotal moments on the slopes of these four climbs from the last few years.
Carnage on the Cormet de Roselend - 2007
In a dangerous break which yielded him the maillot jaune virtuel, Michael Rogers was enjoying his best Tour de France ever. The Australian looked set to take the ascendency in the race, until a crash on the descent of the Cormet de Roselend destroyed his hopes of a yellow jersey.
The casing on his tyre blew out and he was sent sprawling, breaking his collarbone and abandoning the race amid tears during the stage. It was a painful day for Australian fans - after Rogers' crash ruined his race, Stuart O'Grady fell on the same descent, although this spill threatened to ruin more than just his race.
A punctured lung, fractured vertebrae and ribs... O'Grady's life and career was in jeopardy. The Australian being stabilised in a neck brace and transported to hospital was a grim sight - these two riders won't be anticipating another date with the Roselend.
Michael Rasmussen - Cormet de Roselend, 2007
Danish climber Michael Rasmussen had won the mountains classification in the 2005 and 2006 Tours de France. In '07 it was time for a tilt at the main prize. On the 165km stage from Le Grand Bornand to Tignes, Rasmussen unleashed an attack that netted him a solo win and the maillot jaune.
While Le Grand Bornand is the site of the stage 17 finish this year, it was the beginning of Rasmussen's greatest triumph in 2007. Disappointingly, the Dane's success that day would sour a week later when he was withdrawn from the race for lying about his whereabouts in the lead up to the Tour.
Floyd Landis - Col des Saisies and Col de La Colombière, 2006
Having bonked badly on the road to La Toussuire the previous day, Phonak's Floyd Landis blasted his blues away on the sun-drenched journey to Morzine during the 2006 Tour. Embarking on an amazing solo attack upon the slopes of the Col des Saisies, Landis put it in the biggest gear he could and began to motor his way to the front of the field, leaving his teammates to deal with race leader Oscar Pereiro behind.
Landis met the remnants of the leading group on the Col de La Colombière, with Patrik Sinkewitz the last man between the American and open road. He then continued at an infernal pace until the finish in the alpine town of Morzine.
The ride defined the term 'incredible' - after it was found he had tested positive to synthetic testosterone following the stage, Landis' performance lost the credibility everyone had wanted it to possess. Fans, the media and the race organisation wanted to believe in it, but the results from the laboratory at Châtenay-Malabry just days later meant the American's crown was handed to Oscar Pereiro.
Col de Romme - will history be written in 2009?
This climb is new to the Tour de France. At 8.8km with an average gradient of 8.9 percent, this ascent comes after the Cormet de Roselend, Col des Saisies and Col d'Araches. Given that the field will already be blown into several pieces, throwing in a challenge such as this is a piece of ASO magic aimed at further mixing up the general classification. It could well be the launching pad for an ambitious group that fancies its chances overall.