The frontier walls built by different Chinese dynasties have multiple courses. Collectively, they stretch from Liaodong in the east to Lop Lake in the west, from the present-day Sino–Russian border in the north to Taohe River in the south; along an arc that roughly delineates the edge of Mongolian steppe. A comprehensive archaeological survey, using advanced technologies, has concluded that the walls built by the Ming dynasty measure 8,850 however, the entire wall with all of its branches measures out to be 21,196 km .[5] Today, the defensive system of Great Wall is generally recognized as one of the most impressive architectural feats in history.

圖片編號： 162342925
拍攝者： Mauriehill