The Great Wall is the greatest Chinese ancient fortification in order to protect China from the attack of barbarians in the north and it is the only man-made construction can be seen from the outer space. The construction of the Wall starts from 3rd Century BC, covered 6,350km at that time from Shanhai Pass on the Bohai Gulf to Lop Nur in Xinjiang Uygur Autonomous Region. The first major wall was built during the region of Emperor Qinshihuang. He ordered to join several of the Walls in order to keep Barbarians out of his territory. The Wall was maintained by several dynasties after Emperor Qinshihuang. In the Ming Dynasty, the biggest construction of the Great Wall started. The more advanced technology and long-lasting material were used this time, that was the reason the Great Wall is still visible today. The Ming Dynasty Great Wall begins from Shanhai Pass, and ends at Jiayu Pass in Gansu Province, covering more than 6,000km, spanning 9 provinces and 100 counties. The Manchu People conquered the Great Wall by convincing the famous Ming Dynasty general Wu to open the Shanhaiguan Pass. After the Qing Dynasty was established by Manchu people, the Great Wall lost its martial value completely.
Millions of worker had worked on the Great Wall and all of the workers were under the perpetual danger.
The wall is complemented by defensive fighting stations, to which wall defenders may retreat if overwhelmed. Each tower has unique and restricted stairways and entries to confuse attackers. Barracks and administrative centers are located at larger intervals. In addition to the usual military weapons of the period, specialized wall defense weapons were used.
There are several sections of the Great Wall in Beijing. The Mutianyu Great Wall is 70 km from Beijing, and regarded as the most beautiful section. Badaling Great Wall is located in the north of Beijing which is the first one opened to the tourists. Simatai Great Wall is linked with the Jinshanling Great Wall, trekking between those two sections is quite popular.
