The road from Mazzo di Valtellina to Passo della Foppa or the Passo del Mortirolo is one of the most demanding climbs in professional road bicycle racing, having been used in the Giro d'Italia stage race many times. In May 2004, while training in Italian Alps, Lance Armstrong said that it was the hardest climb he had ever ridden. Passo della Foppa or the Passo del Mortirolo at 1852 m. The ascent to this mountain pass starts in Mazzo di Valtellina (there is an alternative from Grosio). The lentght is 12.5km, the heightdifference 1300m. And the maximum slope is 18%. The pass is closed in wintertime.