Beijing is one of China's "Eight Ancient Capitals" and has 7 world heritage sites. It is the city with the largest number of cultural heritage projects in the world. It is a city with a history of more than 3,000 years of city construction and more than 860 years of capital construction. It is a famous cultural city with many historical places of interest and cultural landscapes. Beijing, the capital, is a world-famous ancient city. There are many cultural relics and historic sites in Beijing, all of which make people forget to leave. However, the most mysterious thing among them is probably the ancient city wall in Beijing. Friends who have been to Beijing, have you ever noticed why a corner is missing in the northwest corner of the city wall?
This deviates from the ancient Chinese thought that the sky is round and the earth is round. According to Chinese literature, the theory of Gaitian has been widely popular. Some people believe that the representative artifact of the Liangzhu Culture period, the "jade cong", is the theory of Gaitian. A symbol, the shape of "Cong" is "round sky and square earth". It is an annotation of "the unity of nature and man". Traditional Chinese culture advocates "the unity of nature and man" and pays attention to imitating nature. The principle advocated in Feng Shui is a special annotation of this cosmology.
According to research, the existing old city wall of Beijing began to be built in the Yuan Dynasty and finalized in the Ming Dynasty. In 1215 AD, the Mongolian army occupied Zhongdu City and burned down the palace city, but the Daning Palace on the outskirts survived. In the fourth year of Yuan Dynasty (AD 1267), Kublai Khan, the founder of the Yuan Dynasty, built a large-scale new city - Dadu, centered on Daning Palace. This huge project took 4 years. The construction of Dadu in the Yuan Dynasty opened a new chapter in the history of Chinese urban architecture.
It embodies the traditional Chinese capital building principle of "the former dynasty and the later market, the ancestors on the left and the society on the right" in the design of the whole city. The palace city of Dadu in the Yuan Dynasty was located on the east coast of Taiye Lake (now Beihai and Zhonghai). The center of Miyagi is located exactly on the central axis of the city. The Longfu Palace and Xingsheng Palace were built on the west bank of Taiye Pool respectively. A city wall was built around the three groups of palaces, which later became the Imperial City. The entire imperial city constituted the "former dynasty". Behind the imperial city (today's Bell Tower and Drum Tower are the norm, "Book of Rites" says: "The city is designed according to the rules, and the square and the circle cannot be deceived. This picture of the Nenchi, which was modified by Zhu Yuanzhang, was a reminder to the world, which also led to the city built in the Ming Dynasty. Most of them follow this pattern, that is, one corner is missing from the four corners. Therefore, the four walls of Beijing do not form a rectangle. Its northeast, southeast, and southwest corners are neat right angles, while the northwest corner from Deshengmen to Xizhimen is an oblique angle. .
Some historians and archaeologists believe that the northern city wall of the Yuan Dynasty, five miles north of the present-day Deshengmen and Andingmen, still has striking remains. What's more, its northwest corner is at a right angle. When the city of Beijing was rebuilt in the Ming Dynasty, the northern part of the city was abandoned for the convenience of defense, and a new western section of the northern city wall was built five miles south of the original city wall. At that time, the narrowest part of Jishuitan turned to the southwest, separating the western end of Jishuitan from the outside of the city, so the northwest corner became an oblique angle. In the early Ming Dynasty, the water in Jishuitan was much deeper and the area was much larger than it is now. For the needs of city defense and construction, it is reasonable for the city wall to be angled according to the terrain. Therefore, this view is accepted by most people.
In recent years, some geologists have put forward different views. . When they studied satellite photos, they found that there happened to be a fracture running parallel to the city wall just outside the northwest corner. They called this fracture Chegongzhuang, which is the Deshengmen fracture. However, on the outside of the corner, A faint image of a right angle can be seen in the satellite photos. This may be the image of the old wall foundation on the opposite side. Therefore, some geologists put forward the idea that the northwest corner of the city wall was probably also built at a right angle when it was first built. , the northwest corner of the city wall was broken diagonally. Since the foundation was built on the fracture zone, and the fracture probably still had some weak mobility, the solidity of the city wall was probably affected by multiple collapses. The city wall was transformed into the current oblique style. In this way, the city wall cleverly avoided fractures and could survive forever.
Since there are no precise records of this in ancient books and history books. People are still not sure which statement is the historical truth. To find all the answers to the question, further exploration, analysis and research by scholars will undoubtedly be required.