WALK ALONG THE GREAT WALL | China

You’re going to want to build up some stamina for this one. Snaking its way along the historical border between China and Mongolia, the Great Wall of China is about 13,171 miles and takes an average of 17 months to complete fully. Most people, however, opt to get on and off at various entry points, a more feasible task that still rewards with views of the countryside, ruins, and more.