Stelvio Pass

Where: Italy

Nestled 9000 feet up in the Italian Alps, the Stelvio Pass packs 48 switchbacks (numbered by stone markers) into 15 miles. Its daunting turns have become a rite of passage for adventure-seeking drivers, motorcyclists and cyclists. Slicing around the mountain in the relative safety of your car, you might feel a swell of thankfulness for your engine. As one of the highest altitude runs through the Alps, Stelvio leaves all but the fittest of cyclists breathless.