The wall of Jinzhongdu was expanded on the basis of Nanjing, Liaoning Province, and the way of expansion was to expand on the east, west and south sides respectively on the basis of the original city site. In a sense, Jinzhongdu is an upgraded version of Nanjing, Liaoning, and the battlements in Beijing are basically square.
It is said that hundreds of thousands of laborers were used at that time to expand Jinzhongdu and build the city wall. For the scene of building a city at that time, there is such a description: "People put a basket, and their left and right hands stand in a row, from Yuanzhou to Yan, and the empty basket enters the basket. People stopped the soil and finished it in a few days. " In A.D. 12 15, the Mongolian army invaded Zhongdu, and a fire burned for a whole month, which completely destroyed the Zhongdu city in Jinzhong. From the Yuan Dynasty to the early Ming Dynasty, there were traces of it, and almost all of it disappeared after Jiajing built the outer city. Nowadays, only around Fenghuangzui village, you can still see some intermittent mounds, which are the traces of the walls of Jinzhongdu.
The Yuan capital was not expanded on the basis of Jinzhongdu, and Jinzhongdu could not be expanded if it was destroyed like that. So people in the Yuan Dynasty had to start a new stove in the northeast of the old Jinzhong capital and build a new version of the new city. The shape of the new city is also rectangular, slightly longer from north to south and slightly shorter from east to west. The walls of the Yuan Dynasty were all made of rammed earth slabs, and the walls were reinforced with columns and cross bars. Such a city wall is easily washed away by rain in rainy days. In order to solve this problem, people used reeds and pipes to waterproof the top of the city wall. The new edition of this city is made up of a simple version of the city wall. No wonder it was demolished in the Ming Dynasty. There were eleven gates in the capital of the Yuan Dynasty. At present, the observatory on the south side of Jianguomen is the former site of the southeast corner building of Yuan Metropolis.
Ming Chengzu decided to demolish the existing capital of Yuan Dynasty and build a new official version of Beijing City. Its area is 62 square kilometers. It shrank the north wall of the Yuan Dynasty by 2.5 kilometers and pushed the South City to the front door. The names of the city gates are Zhengyangmen, Chongwenmen, Xuanwu Gate, Chaoyangmen and Fuchengmen. These names are still in use today, but the towers have disappeared. 1564 the outer city surrounded by the southern suburbs was built in the Ming dynasty, which is what people used to call the outer city of Beijing. By the Ming Dynasty, the center of the whole city moved south. Yongdingmen, the outer city gate, the starting point of the central axis. The whole city wall presents a balanced and symmetrical aesthetic pattern around the central axis.
After the Qing Dynasty made Beijing its capital, it did not make a new edition, but followed the model of the Ming Dynasty. Different from the Ming dynasty, it is only in the system of dividing the flag and the people into cities. The inner city is centered on the imperial city and divided into four corners by the Eight Banners. Two yellow flags live in the north: the yellow flag is located in Andingmen and the yellow flag is located in Deshengmen; Two white flags live in the east: the white flag is in Chaoyangmen and the white flag is in Dongzhimen; Two red flags live in the west: the red flag is embedded in Fuchengmen and the red flag is located in Xizhimen; The two blue flags live in the south: the inlaid blue flag lives in Xuanwumen, and the zhenglan flag lives in Chongwenmen. In the eighth year of Shunzhi (165 1), Chengtianmen was rebuilt and renamed Tiananmen Square.
19111June 10, the Revolution of 1911 broke out, the Qing Dynasty was overthrown, and Beijing's history as the imperial capital of the feudal dynasty ended. Chinese Civilization, written at the beginning of last century, described the city walls at that time. The book says that the city of Beijing at that time was divided into an inner city and an outer city, both of which were surrounded by solid walls. At that time, the tourists who came to Beijing "decided to climb the city wall first". The author of the book was shocked by the growth of the city wall, praising the city wall of Beijing as "a real golden city with iron walls" and standing on the city wall "can best capture the grand view of Beijing".