Scanuppia-Malga Palazzo is the name of a brutally steep climb located in Besenello,a municipality in Trentino in the northern Italian region Trentino-Alto Adige/Südtirol.
Tucked away in the Riserva regionale Scanuppia, it’s said to be the steepest hardest long climb on a sealed-surface road in Europe (or the world), hitting a 42,8% of maximum gradient through some of the ramps. The road, also known as Salita Scanuppia, follows a road built in the XVIth century. The ascent is 7.5 km (4.66 miles) long. Over this distance the elevation gain is 1.317 meters and the average percentage is 17.6 %. Without marked central lines, the road climbs up from 198 meter to 1,515 meter above the sea level.
Set high in the Dolomite mountain range, the road is paved (with concrete parts). What makes it even more difficult is that much of the concrete surface is not "even". Not that it's "rough" (though in a few spots it is that) - but that it's "wavy", like with very wide "ripples" in its surface. This unevenness is intended to provide better traction when there is snow or ice.
-around 12% for about +120 vertical meters as a "warmup"on the wider asphalt road
-around 24% for about +375 meters in lower section of narrow concrete road.
-around 14% for about +135 meters.
-around 17-19% for about +660 meters