Col du Sanetsch

Reputedly the most demanding climb in Valais, Sion up to the 2250m col and Lac de Senin.

The Sanetsch road climbs hard out of Sion through vineyards and forest to a 2250m col below the western Bernese Alps, ending at the Lac de Senin reservoir. It cannot be driven all the way over to Gsteig, so it is an out-and-back, but it is often called the toughest paved ascent in Valais with ramps near 14.5 percent. The upper road is narrow and exposed. Mind the steep narrow sections that demand low gears, the tunnels and rockfall zones on the climb, and the dead-end at the lake where you must turn back.