Chanajiga
Chanajiga is a high mountain pass at an elevation of 1.186m (3,891ft) above the sea level, located on the northern part of the island of Tenerife, which forms part of the Canary Islands, Spain. The climb is simply terrible with sections up to 30%.
The road to the summit is asphalted but includes some narrow and really steep sections. Starting from Los Realejos, the ascent is 6.9km long and the elevation gain is 963m. The average percentage is 14.05% but the maximum slope is 30%.