Tianmen Mountain in Zhangjiajie, China

One step at a time

Taking the stairs is a great way to build more exercise into your daily routine but if you really want to do it in style, look no further than China's Tianmen Mountain (translated: Heaven's Door or Heaven’s Gate). About 5,000ft above sea level, the hole in the mountain is the highest naturally formed arch in the world. Originally a cave, it became an arch in 263 AD when the backside of the mountain collapsed, creating the dramatic opening we see today. You'll have to climb 999 steps to make it to the top, but we promise, the view makes it all worth it.