The mountainous range that divides the Blenio Valley from the Leventina Valley,
offers bikers several crossing possibilities, one of which is the “Passo Castrumo”, a pass that connects two beautiful slopes still little known by mountain bike enthusiasts. Unlike the “Bassa di Nara” tour, this crossing is done from the Leventina Valley towards the Blenio valley. The starting and ending point of the route is the town of Acquarossa. We descend towards Biasca along secondary and dirt roads and bike up the Leventina valley on the bicycle lane to Giornico. After passing the Biaschina hairpin bends on the cantonal road, we get to Calonico by cycling along the “Strada delle Vigne”(Vineyards road).