1 Located 40 miles (65km) to the north of Beijing city proper, the Mutianyu Great Wall section measures 23 to 26 feet (7 to 8 meters) in height, 12 to 15 feet (3.6 to 4.5 meters) in width and 3.4 miles (5.4 km) in length.
The section was first first constructed during the Northern Qi Dynasty (550-557) and consists of 23 watchtowers distributed at close intervals along the wall.
