Foot travel has been the way of the wayfarer since men and women were still dragging their knuckles. The fact that people still opt to walk today, in the age of the wheel and the combustion engine, tells us there is something virtuous and irresistible in the plodding of one foot forward after the other. And without question, walking works. From trekking the Appalachian Trail to following the less-traveled path along the Great Wall of China, good old fashioned walking may be Adventure's preferred mode of transportation. Using their legs and feet, many people have moved thousands of miles overland, and in many places the trails they wore in the earth are used by modern recreational trekkers who follow in the footsteps of their forebears. Here are the world's top 10 treks.