During the Spring and Autumn Period, the Great Wall was first built by the State of Chu, and it was hundreds of miles long. It was called "Fangcheng" (now Fangcheng County, Henan Province). During the Warring States Period, the Great Wall was built in succession in Qi, Wei, Yan, Zhao, Qin and other countries.

Qin Changcheng: After the Qin Dynasty unified China, the Great Wall in northern Thailand, Zhao and Yan was rebuilt and supplemented, and it became the Great Wall from Lintao in the west to Liaodong in the east. (basically Qin, not in North Korea).

Great Wall of Han Dynasty: The Great Wall of Han Dynasty starts from Liaodong in the east and reaches "Now Luobo" in Puchanghai in the west, with a total length of 10000 km. It was built by Emperor Wu of the Han Dynasty on the basis of conquering Zhu Nu three times, and it was the largest, which not only resisted Zhu Nu's going south, but also protected the Silk Road.

Great Wall in Ming Dynasty: In order to prevent the invasion of Tatars and tiles, the Great Wall was built many times in Ming Dynasty, starting from Jiayuguan in Gansu Province in the west and ending at Hushan in Dandong, Liaoning Province in the east, with a total length of more than 6,000 kilometers.

City wall: As the main building of the Great Wall, it is based on the principle of "different places, using local materials and teaching students in accordance with their aptitude". There are stacked walls on the outside, observation ports on the upper part and shooting holes and stone holes on the lower part.

Enemy platform: riding over the wall, outside the trunk wall, you can shoot people from the side, so that the two stations can cooperate with each other and stop the city. You can build an enemy tower on the enemy platform, with a crib on the upper floor, an arrow window on the middle floor and artillery on the lower floor. The building can shelter from wind and rain and rest, and can also store weapons.

Beacon tower: It is usually built on the mountain near the Great Wall. In case of enemy situation, burn cigarettes during the day and set fire at night. Tell the approximate number of invading enemies by the number of guns, and pass them on station by station to inform the enemy situation.