The toughest climbs of the Tour de France 2023

The decisive mountains that could decide who reaches Paris in the yellow jersey

Mountain passes are what give the Tour de France many of its iconic settings. They are witness to epic battles, legendary tales, and unexpected victories, dating right back to the very start of the race. These climbs have become pivotal in determining the wearer of the coveted yellow jersey, and ultimately, the champion of the prestigious Grand Tour. And this year’s route has certainly focused on the mountains. 

Taking in all France has to offer, including the Alps, the Pyrenees, the Jura Mountains and the Puy de Dôme in the Massif Central. It is safe to say that this year's route is designed for those who relish the challenges of climbing, and then climbing some more. From the very beginning, stage one presents punchy climbs in the Basque Country before the peloton makes its way to France for the real mountain tests. 

With so many notorious climbs making a comeback for the 110th edition of the Tour, we’ve highlighted some of the toughest climbs the riders will have to tackle in the next 21 days. 

Col du Tourmalet - stage six 

The Col du Tourmalet is one of the most famous mountain passes in the Tour de France having been visited the most times throughout the race’s history. It’s not the longest, the steepest or the tallest mountain climbed in the Tour, but perhaps the hardest combination of all three elements. When the Tourmalet is involved, there is always a story to be told – even the way it was founded is a tale worth reading

The legendary climb, located in the French Pyrenees, made its debut in the Tour in 1910. Octave Lapize conquered its treacherous slopes, at times even dismounting to push his bike up the brutal inclines. The Tourmalet's most recent appearance was in 2021 when the peloton raced from Pau to Luz Ardiden, and it was French rider Pierre Latour who crested the climb first.  

The Tourmalet last featured in 2021 on stage 14 of the Tour (

Throughout its history, the Tourmalet has served as the finish line only three times, most recently in 2019, where Thibaut Pinot triumphed, delighting his French supporters on one of the country's most hallowed climbs. Prior to this, the Tourmalet hosted the finish in 2010, when Andy Schleck claimed the win, and 1974, when Jean-Pierre Danguillaume won. 

In this year’s edition, the peloton will face the mighty Tourmalet on stage six from Tarbes to Le Cambasque. A lengthy 17.1 kilometres in length, this particular side of the mountain averages a gradient of 7.3%, and really tests the riders with some punchy gradients at altitude. Standing over 2,000 above sea level, the riders will be thankful for a long descent on the other side before they begin climbing again to Cauterets-Cambasque for the summit finish, rounding off one of the more brutal days in the saddle. 

Puy de Dôme - stage nine, summit finish 

Wrapping up the first week of this year’s Tour de France is the legendary Puy de Dôme, a volcano in the Chaîne des Puys region of the Massif Central. The climb has not featured in the Tour for 35 years, despite having been a regular feature from its debut in 1952 until 1988. 

The climb has been witness to some of the race’s most historic moments, such as the battle between Raymond Poulidor and Jacques Anquetil in 1964, as well as the unfortunate incident in 1975 when Eddy Merckx was punched by a spectator. Notable winners of this prestigious climb include Fausto Coppi in 1952 and Federico Bahamontes in 1959 when the riders had to tackle the Puy de Dôme in a 12km-long mountain time trial. 

The iconic Puy de Dôme will make its comeback after a 35-year hiatus (James Startt)

The Puy de Dôme has actually been closed to cyclists since 2012, and this is the first time the relentlessly steep climb will be the summit finish after a long absence. The climb is 13.3 kilometres in length and sits at 7.7% average gradient as it winds its way around the volcano in the middle of France. While the climb is set to make for spectacular viewing, there will be no spectators allowed on the Puy de Dôme on the day of the race. 

Col du Grand Colombier - stage 13, summit finish 

In the south of the Jura Mountains, the Col du Grand Colombier was first visited by the Tour de France in 2012 on stage 10. The leader over the summit was Thomas Voeckler who went on to take the stage victory in Bellegarde-sur-Valserine. The climb returned as a summit finish in 2020, with Tadej Pogačar taking the stage. 

Three years later, the pass will feature again as stage 13’s summit finish. It has a length of 17.4 kilometres and an average gradient of 7.1%, peaking at 12% in certain sections. Pogačar completed this climb in an impressive 45 minutes and 37 seconds when he won here.

Read more: How long is the Tour de France? 

Col de Joux Plane - stage 14 

Located in the Alps, the Col de Joux Plane is set to feature in stage 14 of this year’s Tour, marking its 13th appearance since its debut in 1978, though it's never been used as a summit finish with every finish in nearby Morzine. Christian Seznec became the first rider to conquer this climb and win in 1978, and most recently, Jarlinson Pantano achieved the feat in 2016.

Not featured for seven years, the Col de Joux Plane returns to the Tour this year, positioned 127km into the stage. A hors catégorie (HC) climb, the riders will ascend the mountain pass for over 11 kilometres at an average gradient of 8.5%. Not only does its high average gradient tell us how demanding this climb will be, but it comes after four other categorised climbs from earlier on in the stage, so accumulated fatigue will add to the challenge. 

Col de la Loze - stage 17 

Situated in the heart of the French Alps, the Col de la Loze ranks as the seventh highest mountain pass in France. Remarkably, a path up the mountain was only opened in May 2019 and has since been featured in just two bike races: the 2019 Tour de l’Avenir and the 2020 Tour de France. 

Miguel Ángel Lopez won the stage that finished atop the Col de la Loze in 2020 (Getty Images)

In the 2020 edition of the Tour, the Col de la Loze was chosen as the summit finish and proved a formidable challenge. Colombian rider Miguel Ángel López emerged victorious, with Tadej Pogačar, sporting the yellow jersey, 15 seconds behind. Even Pogačar called the climb a “monster” – and that’s coming from the man who won the Tour on his debut… 

Making its return for the 2023 edition, the Col de la Loze stands tall right near the end of stage 17. With a distance of 28.1km and an average gradient of 6%, there will be big gaps and those with strong mountain legs will slog it out on the climb as it peaks to a maximum gradient of 24%. Coming after the second rest day may help some riders, but if Pogačar called it a monster in 2020, stage 17 won’t be an easy day for the riders, but it’ll be a great one for those watching. 

Read more: How to watch and live stream the 2023 Tour de France

Cover image by Alex Broadway/SWPix

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