Slide 32 of 44: This spectacularly steep and winding road can be found in the Tianmen Mountain National Park in China's Hunan Province. It curls up the mountain for seven miles (11km) with 99 nerve-wracking bends and precipitous drops. The road ends at a natural gap near the mountain's peak. Although, you'll need to walk 999 steps after you've parked to reach the sacred crevice, which is known as Heaven's Door.