Research topic: Great Wall of China

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). It averages 25 ft ... Read more