A tricky scenic road to Alto de Trobaniello
Alto de Trobaniello is a mountain pass at an elevation of 1.625m (5,331ft) above the sea level, located in the Autonomous Community of the Principality of Asturias, Spain. The road is unsurfaced, but smooth enough for cars.
The road to the summit starts paved. But after 5 km, at 752m above the sea level, the last part of the climb is unpaved with concrete parts. The steepest kilometre is between 12,5km and 13,5km into the climb (so starting at 3,5km from the summit) - this averages out at no less than 12,7%!
Starting from Santa Marina, the ascent is 17 km long. Over this distance, the elevation gain is 1.068 meters. The average percentage is 6.3 %. There are sections over the 15%. The first part of the climb is fairly unassuming, on fine tarmac through typical Asturian mountain villages. It really eases the riders in as well, with the first 6km, the only ones on tarmac, averaging a mere 4,8%, with the last of these the steepest, at 6,9%. After that, however, apart from a couple of short stretches, it is all sterrato, and it's getting ever steeper.