With its 2,770 meters, the official summit of the Col de l’Iseran is the highest paved pass in Europe.
The Cime, an artificial loop around the Bonette, is claimed by many – from the Ubaye valley – as being higher.
While mathematically correct, the official pass height of the Bonette is 2,715 meters.
The Iseran, the Stelvio (2,758) and the Agnel (2,744) are higher ‘by nature’…
Geography
The Iseran is part of the Route des Grandes Alpes (in French).
It connects the valleys of the Isère (Tarentaise) and Arc River (Maurienne) between Val-d’Isère in the north and Bonneval-sur-Arc in the south.
The north side of the pass officially starts at Val-d’Isère, or further down from Bourg-Saint-Maurice.
The climb from the south officially starts at Lanslebourg-Mont Cenis, but you could also consider Modane as the starting point.
Tour de France
Post WWII the Iseran was included in the Tour de France 6 times between 1947 and 2019.
In 1996 it was also scheduled, but that stage was rescheduled due to bad weather: snow on both the Iseran and the Galibier.
In 2019, the southern ascend was again included, in stage 19, which was scheduled to finish in Tignes.
And that stage eventually got neutralized at the Iseran summit, because of bad weather and a landslide.
Bourg-Saint-Maurice
Starting from Bourg-Saint-Maurice, the climb to the summit of Col de l’Iseran is 47 (!) kilometers.
Over this distance, the road ascends over 2,000 meters – a modest average grade of 4.2%.
While that seems rather friendly, the sheer length of the climb makes it a hard one.
Ignoring the 17 kilometer ‘near flat’ sections, the average over the remaining 30 kilometers is close to 6%.
The views higher up, past Val-d’Isere in the hair pins, are fantastic, as is the panorama at the summit.
There’s also a ‘refuge’, L’Èchoppe de l’Iseran.
(Last time I was up there, in 2024, it was closed and looked out of business)
If you go down to Modane, it’s worth taking the ‘Route Panoramique’ at Sollières-Sardières.
It’s more quiet and enjoyable, but it comes with some extra climbing to the Croix d’Aussois.
That is easier from this end: 7.5 kilometers at 3.3% average, with 3.5 kilometers at/over 5%.
I descended towards Modane after my climb from Bourg-Saint-Maurice, with a little ‘detour’ up and down the Mont Cenis.
Thinking this was mainly downhill, I figured it would be relatively easy.
However, the section in the valley between Bonneval and la Madeleine, completely wore me out because of the strong headwind.
Report of my trip up this end in 2014 here.
Lanslebourg
From the south, the official climb starts in Lanslebourg-Mont Cenis and is 32.2 kilometer long.
With a 1,371 meter elevation gain, this is an average grade of 4.2%.
The first 7 kilometers are, with some 350 altimeters, not the hardest bit, but it has 9% grades.
After that, there’s a 12 kilometer ‘flat’ section through the Bessans valley, where you will hopefully not have a headwind.
If in this section you do have to battle a headwind, it will be a very tough 12 kilometers…
Despite being used to riding headwinds, the famous ‘Dutch Mountains’, I wasn’t happy with it.
(And it also made me wonder if I’m just lucky, since I faced a headwind going in either direction 🤷♂️)
Again, ignoring this flat section, the average of the climb increases to around 6%.
The hardest part, or the final, starts at Bonneval-sur-Arc: 13.4 km with 977 m of elevation (7.3%) with several stretches over 10%.
From this end, you could include the section between Modane and Lanslebourg as a ‘warm up’, adding some 23 kilometers with an additional 450 meters of elevation.
These come with some up- and downhill bits, but also here the wind could be your greatest enemy.
Immediately upon leaving Modane, there’s a more scenic and quiet route, if you travel the D215 and continue the on the D83 near Aussois.
This is the ‘Route Panoramique’ – at the roundabout, turn left towards Le Bourget and Aussois.
It features an additional climb to the Croix d’Aussois: 8.6 kilometers at 5.4%, with a kilometer over 8%.
I cycled up this “intermediate” to continue to Plan du Lac, a fork off the Iseran in my 2021 Tour de France.
There’s a “freebie” col to be had from this end: just past the first hairpin section out of Lanslevillard, there’s a “Col de la Madeleine” (1,746m) marker.
Definitely not THE Col de la Madeleine, but still 😎
As mentioned above, there’s a ‘refuge’ for a snack and/or a souvenir at the summit of the Iseran.
(Last time I was up there, in 2024, it was closed and looked out of business)
Report on my 2021 ascend starting just outside of Sollières, here, and that of about the same trip in 2024 here.
From the latter, I made a clip with some parts of this ascend and you can find that on my YouTube channel.
Tignes – Val Claret
If you’re in the mood, you can get to Tignes from either end, although from Lanslebourg you’ll have a flying descend to Val d’Isère first.
From the south: before Val d’Isère, turn towards ‘Tignes – Les Brévières’ at Le Villaret.
From the north: past Val d’Isère, turn towards ‘Tignes – Val Claret’ at le Chevril.
The former is a bit longer at 9.5 kilometers, against 8 kilometers for the latter, but the altitude gain is the same, some 560 meters.
I’ve done both: in stage 7 of my TDF 2021 and stage 5 of my TDF 2024, although I was coming from the north end on both occasions 😎
In 2024 I cycled Val d’Isere – Tignes in the pouring rain… The Iseran descend before that is on My YouTube channel too.
Here’s the 2021 descend:
