The Great Wall of China is a Chinese fortification built from the 3rd century BC until the beginning of the 17th century, in order to protect the various dynasties from raids by Hunnic, Mongol, Turkic and other nomadic tribes coming from areas in modern-day Mongolia and Manchuria. Several walls were built since the 3rd century BC, the most famous being the Great Wall of China built between 220 BC and 200 BC by the first Emperor of China, Qin Shi Huang (this was located much further north than the current Great Wall of China built during the Ming Dynasty, and little of it remains).Great Wall of ChinaThe Great Wall is the world's longest man-made structure, stretching over a formidable 6,352 kilometer, from Shanghai Pass on the Bohai Sea in the east, at the limit between "China proper" and Manchuria (Northeast China), to Lop Nur in the southeastern portion of Xinjiang Uygur Autonomous Region. Along most of its arc, it roughly delineates the border between North China and Inner Mongolia.