Photograph by Michael Yamashita
Dipping and soaring like the wind-whipped tail of a kite, the Jiankou section of the Great Wall of China runs along sharp mountain crests. This stretch is one of the "wild wall" sections, those that have not been rebuilt. The Great Wall is not a single construction but a series of defensive walls built sporadically by a succession of rulersat a monumental cost in human toil, injury, and death. The exact combined length of its sections remains unknown.