The Iseran is the roof of the Alps, as far as paved passes go. At 2,764 metres, it is the highest of the great Alpine passes, a shade above the Stelvio, and the road over it was opened in 1937 to link the Tarentaise valley with the Maurienne, a feat of engineering that took years of work in short summers. It goes through the heart of the Vanoise National Park, France's first, created in 1963 to protect the ibex, which had been almost wiped out by hunters, and the park's work has been a success, as there are thousands now.
From Val-d'Isère, the road climbs through bare, glacier-carved terrain in big, open hairpins, with the peaks of the Vanoise glittering above, and the grass gives way to rock and old snow. The summit is a small, windy plateau with a stone chapel and a monument, and a marker to pose with. Beyond it, the south side drops towards Bonneval-sur-Arc, one of the loveliest villages in France, with stone houses and slate roofs. The surface is variable, and even in summer, you can find snow, ice or cold fog at the top. In June and often in autumn, the road may be closed by snow, and it is generally shut from about November until June.
Weather at this altitude is no joke. Temperatures can be ten degrees below those in the valley, and storms form quickly in the afternoon. A windproof layer and warm gloves are essential. On a clear day, however, the visibility is spectacular, with the Grande Casse, the highest point entirely within the Vanoise, and the glaciers of the Haute Maurienne visible on the south. You may well see marmots, and if you are lucky, ibex on the rocks.
Fuel is available in Val-d'Isère and Tignes on the northern side, and Bourg-Saint-Maurice, thirty kilometres away, has the full range of services. On the southern side, the villages are tiny, so make sure you have enough fuel for the descent to Lanslebourg. In season, a small stand near the top may sell hot drinks, but do not rely on it. Ride early, avoid weekend crowds, and remember that on this one, the point is the height.