Great Wall of China

Great Wall of China Defensive frontier and world heritage site, c.2400km (1500mi) long, extending from the Huang Hai (Yellow Sea) to the Central Asian Desert, n China. It is an amalgamation of fortifications constructed by various dynasties. The Warring States built the first sections of the wall. In 214 bc, Qin Shihuangdi ordered that they should be joined to form a unified boundary. The present wall was mostly built 600 years ago by the Ming dynasty. It averages 7.6m (25ft) high, and is up to 9m (30ft) thick.

Great Wall of China fortifications, c.1,500 mi (2,400 km) long, winding across N China from Gansu prov. to Hebei prov. on the Yellow Sea. The wall, running mostly along the southern edge of the Mongolian plain, was erected to protect China from northern nomads. It is an amalgamation of many walls built in ancient times; the first unified wall was built in the 3d cent. BC by the Ch'in dynasty. Laborers were conscripted from all over China to build it, and many of them died during the project. The wall's present form dates substantially from the Ming dynasty (1368-1644), and wall building was particularly intense in the late Ming period. The wall averages 25 ft (7.6 m) in height and is 15 to 30 ft (4.6-9.1 m) thick at the base, sloping to 12 ft (3.7 m) at the top. Guard stations and watchtowers are placed at regular intervals. The eastern part of the wall is earth and stone faced with brick, but in the west it is merely a tamped earth mound. Successive invasions of China from the north demonstrated that the Great Wall had little military utility. The Ch'ing (Manchu) dynasty (1644-1912) did not use the wall and largely abandoned it. Since 1949 two sections N of Beijing have been reconstructed and are open to visitors.

Bibliography: See A. Waldron, The Great Wall of China (1990); J. Lovell, The Great Wall.

Great Wall of China A defensive wall in northern China, extending over a total distance of 6700 km (4200 miles) from the Jiayuguan Pass in Gansu province to Shanhaiguan on the Yellow Sea north of Beijing. Its origin dates from c.210 BC when the country was unified under one ruler ( Qin Shi Huang), and the northern walls of existing rival states were linked to form a continuous protection against nomad invaders. It was rebuilt in medieval times largely against the Mongols, and the present wall dates from the Ming Dynasty (1368–1544). Although principally a defensive wall it served also as a means of communication, and is said to be the only man-made feature that would be visible from a space orbit.