The Great Wall of China.

The Great Wall, whose building started more than 2,000 years ago, represents a main part of Chinese history, which has a profound influence on China today. So to speak, the Great Wall, in a sense, is history. And you will see that this tendency is reflected in our content. We generally talk about the Great Wall with dynasties who built it, along with events and social aspects of those dynasties, which may branch out as far as to other topics. In this manner of narration, It can be a little loose and sightly off the point, but we think it interesting, and it makes sense to put the Great Wall into the Chinese history.
The Great Wall of China is a series of fortifications made of stone, brick, tamped earth, wood, and other materials, generally built along an east-to-west line across the historical northern borders of China in part to protect the Chinese Empire or its prototypical states against intrusions
by various nomadic groups or military incursions by various warlike peoples or forces. Several walls were being built as early as the 7th century BC; these, later joined together and made bigger and stronger, are now collectively referred to as the Great Wall. Especially famous is the wall built between 220–206 BC by the first Emperor of China, Qin Shi Huang. Little of that wall remains. Since then, the Great Wall has on and off been rebuilt, maintained, and enhanced; the majority of the existing wall was reconstructed during the Ming Dynasty.
Other purposes of the Great Wall have included border controls, allowing the imposition of duties on goods transported along the Silk Road. regulation or encouragement of trade and the control of immigration and emigration. Furthermore, the defensive characteristics of the Great Wall were enhanced by the construction of watch towers, troop barracks, garrison stations, signaling capabilities through the means of smoke or fire, and the fact that the path of the Great Wall also served as a transportation corridor.
The Great Wall stretches from Shanhaiguan in the east, to Lop Lake in the west, along an arc that roughly delineates the southern edge of Inner Mongolia. A comprehensive archaeological survey, using advanced technologies, has concluded that the Ming walls measure 8,850 km (5,500 mi). This is made up of 6,259 km (3,889 mi) sections of actual wall, 359 km (223 mi) of trenches and 2,232 km (1,387 mi) of natural defensive barriers such as hills and rivers.Another archaeological survey found that the entire wall with all of its branches measure out to be 21,196 km (13,171 mi).
The Great Wall was originally built in the Spring and Autumn, and Warring States Periods as a defensive fortification by the three states: Yan, Zhao and Qin. It went through constant extensions and repairs in later dynasties. It began as independent walls for different states when it was first built, and did not become the "Great" wall until the Qin Dynasty. Emperor Qin Shihuang succeeded in his effort to have the walls joined together to fend off the invasions from the Huns in the north. Since then, the Wall has served as a monument of the Chinese nation throughout history
The mystery of the construction of the wall is amazing. The construction, which drew heavily on the local resources for construction materials, was carried out in-line with the local conditions under the management of contract and responsibility system. A great army of manpower, composed of soldiers, prisoners and local people, built the wall. The construction result demonstrates the wisdom and tenacity of the Chinese people.
Great Wall carries a considerable part of Chinese culture. It has long been incorporated into Chinese mythology and symbolism. The most well-known legend is about the collapse of a section of the Wall caused by Meng Jiangnu, who cried bitterly over the death of her husband after he died while building the wall. This legend has been spread widely through textbooks, folk songs and traditional operas.