Chengchi, also known as Chengguo, is an ancient Chinese military defense building, mainly based on walls and pools, and the city walls will basically have doors, so after closing the city gate at night in ancient times, will there be other paths that can sneak out of the city?
China's early city walls were mainly made of soil, and it was not until after the Ming Dynasty that bricks began to be wrapped, but China mastered the technology of building walls very early on, which was called banzhu, that is, "banzhu" of "Fu said to lift between banzhu". With the engraving technique, the walls tend to be stronger and increase their climbing difficulty. So, after the city gates are closed, can people sneak out of the city? The answer, of course, is no.
From a military point of view, the weakest link of a city is mainly in the city gate, so the design of the city gate is particularly important, many enemies will start from the city gate, start to attack, if the city gate is broken, it also means that the city is finished. In order to defend against foreign enemies and some chicken and dog thieves, when it is almost dark, the city gate will be closed, and at this time, the bandits and kings in the mountains will not take advantage of the darkness to enter the city, and prevent foreign enemies from sneaking in. Therefore, in order to maintain law and order, the people who designed the city wall basically did not let it have the opportunity to contact the path, let alone have a path.
If there is such a small road, the city gate is useless, after all, any secret is not a secret, as long as there is a heart to explore, this path will always be known by the enemy, then the city is in danger. There are several stories in history that can prove that there is no trail that allows people to sneak into the city.
During the Spring and Autumn Period, one day when the rain was like numbness, Yanagi xia Hui and a girl were blocked outside the city gate and could only go to the temple to avoid the rain. By the end of the night, the weather turned cold, and the woman was awakened by the cold, and got up and begged to sit in Yanagi's arms to ward off the cold. However, in ancient times, this was offensive, so Yanagishita shook his hand and rejected this suggestion. But the woman's words were nothing to say, he hugged the woman, his heart was not distracted, so he spent the night, so Yanagishita Hui's reputation for sitting in peace was also spread.
Many people may think that Liu Xia Hui is just an ordinary person, so he can't enter the city, but he was called "Yimin" by Confucius, and the princes of various countries competed to hire him with the high-ranking official Houlu, which showed his high status.
In addition, Zhao Kuangyin's father had also faced such a situation. In the Later Zhou Dynasty, Zhao Kuangyin had not yet shown his ambition, and he worked under Chai Rong. Once, when Hou Zhou was conquering southern Tang, he was responsible for defending the city, and his father Zhao Hongyin, who had just returned to the city with troops from the front line, asked Zhao Kuangyin to open the door and let him go home. But it was dark, and Zhao Kuangyin couldn't fully identify that it was his father, and in case something happened at night, he couldn't get away with it, so he said that he couldn't let him into the city without the emperor's order, and Zhao Kuangyin's father could only blow a cold wind outside the city gate for a night.
Although there is no trail, but sometimes there is a military report, what should be done in this case? If it is in a relatively peaceful era, if it is confirmed that it is a general, the soldier can put down a hanging basket or a rope ladder from the city gate, and the person will pull it up. However, if it is a big war, soldiers will not make such a dangerous move because of one person. As for whether there really is a secret path, it can be seen from the above that unless only one person knows about this secret path, it is basically impossible to exist.