Valle di Preda Rossa from Ardenno

The first 9km are smooth on excellent asphalt, the central section invites you to push on. Once you reach the villages of Filorera and Cataeggio you catch your breath, then comes the best part. From here on, cars are only allowed with a pass, so you won't have much company. You climb along the Predarossa valley, which tears up immediately above 10％ and maintains the gradient with a wearisome constancy. 12km of meadows and woods to climb along a stream from an altitude of 900 to 1960m, arriving in a grassy plain at the foot of Monte Disgrazia. In the first section a short descent followed by 2km at 13％ average with peaks at 18％, then a tunnel that allows you to breathe also because you have to stop and turn on the light with a button. Then the steepest section ever, very long ramps between 18 and 24％ to get to the last stables 5km below Predarossa. Further on is the last refreshment stop but you won't stop because the gradient now already allows you to rest a little (6-8％). The last 4.5km winds its way up 17 hairpin bends through the woods, which never seem to end. The descent is spectacular and makes you realise even better how steep some of the kilometres are. I may not be a pro but it was very tough. It deserves this position in the classification.

This ascent takes you below Monte Disgrazia by way of a narrow and in places concrete road.
Be careful, it is often closed due to landslides or maintenance.
There is a tunnel with the possibility of switching on the lights by means of a button.
Very scenic and demanding, especially in the second part.
No refreshments at the finish.
No water fountains along the route.