This spot lies in the Maurienne, the long valley of the river Arc that runs from the high Alps down toward Chambéry, and the town of Modane sits at the heart of it. For centuries this was the way across the mountains to Italy, via the Mont Cenis pass, and in the nineteenth century engineers drove a railway tunnel under the Fréjus massif, which opened in 1871 and gave the town its role as a border station. A road tunnel followed in 1980. Today Modane is quiet and a bit industrial, but its position makes it a natural stopping place.
On the Route des Grandes Alpes, the old tourist road laid out in the early twentieth century from Lake Geneva to the Mediterranean, this valley connects two great mountain sections. To the north lies the Col de l'Iseran, over 2,700 metres, among the highest paved passes in the Alps, and to the west the Galibier, which tops 2,600 metres and is the high point of many riders' year. Both are closed by snow for most of the winter and spring, usually reopening in early summer, so check before you plan.
The riding here is a lesson in scale. The valley is steep-sided, with forts clinging to the slopes, avalanche galleries over the road and a scattering of villages with slate roofs. Weather can change quickly: sun in the valley can mean snow above, and thunderstorms build in the afternoon. Start early and keep warm layers handy. In the valley the road is wide and fast, but the passes demand attention, with hairpins and sheer drops.
Modane has about four thousand people and offers fuel, a few cafes and a supermarket. If you are heading up toward the high passes, fill the tank here, because stations become scarce higher up. The nearby ski resorts, such as Val Thorens, are on the other side of the mountains, and in summer they are quiet. Carry a rain jacket, and stop to look at the cliffs when you can.