The 10 Hardest Cycling Climbs in the World — Now Rideable Indoors

Featured in the Vuelta a España, the Angliru's ramps above 20% make it nearly impossible to stand on the pedals without slipping.

The Stelvio is the second highest paved mountain pass in the Alps, with 48 numbered hairpin bends on the eastern ascent.

The Giant of Provence is infamous for its exposed, treeless summit and unpredictable Alpine winds. Tom Simpson died here during the 1967 Tour.

The most iconic Tour de France climb, featuring 21 numbered hairpins — each named after a Tour winner.

A Mallorca legend — the road literally ties itself in a knot around the Nus de Sa Corbata loop before reaching the sea.

One of the highest Tour de France passes at 2642m, often combined with the Col du Télégraphe for a monster day in the saddle.

Considered Italy's hardest climb, the Zoncolan east side averages nearly 12% with sections of 22% — a suffer-fest by any measure.

Short but savage — the Mur de Huy punches hard with a 26% maximum gradient and is the legendary finish of La Flèche Wallonne.

The western Bormio approach to the Stelvio offers a completely different character — longer, steadier, and equally spectacular.

A gateway to the Col du Galibier, the Croix de Fer is a rolling Alpine giant — deceptively hard due to its many false summits.