The Great Wall was built in the 5th century BC during the Spring and Autumn Period and the Warring States Period. In the 3rd century BC, Qin Shihuang unified China and sent 300,000 troops led by Meng Tian to chase the Xiongnu in the north, connecting the Great Wall originally built in sections and continuing to build it. Since then, it has been continuously maintained and expanded, and/kloc-0 was built for more than 2,000 years around the middle of the 7th century.

It should be more than 2,500 years since the beginning. ...