The Great Wall in Beijing
To the northwest and north of Beijing, a huge, serrated wall zigzags its way to the east and west along the undulating mountains. This is the Great Wall, which is said to be visible from the moon.
Construction of the Great Wall started in the 7th century B.C. The vassal states under the Zhou Dynasty in the northern parts of the country each built their own walls for defence purposes. After the state of Qin unified China in the Xiongnu tribes in the north and extended them to more than 10,000 li or 5,000 kilometres. This is the origin of the name of the”10,000-li Great Wall”
