Risk Factor: This highway is the second-highest paved road in the Alps (behind France's Col de l'Iseran), climbing to 9,045 feet with gradients as steep as 14%. But what really makes the drivers tremble is the 60 hairpin turns packed into just 15 miles. You can count them as you go along, as 48 of them are numbered and marked by stones along the way. The route achieved further infamy when former Formula One driver Stirling Moss drove off the road during an event.
Why you might be tempted to drive it anyway: For those spectacular Alpine views. Once you complete the pass, you can stop at Stelvio National Park, Italy's largest, to take in the mountain scenery.