Beijing Daily Client | Reporter Han Mei
In the section of the Ming Great Wall in Qinhuangdao City, Hebei Province, there is a physical remains of a Tumen. This is the first discovery of the physical defense facilities of the Great Wall recorded in the book "Mozi" more than 2,000 years ago.
Tumen, the most secret member of the Great Wall Secret Gate family, vividly inherits the architectural, military and cultural wisdom of the ancient Great Wall of China.
In recent years, the team of Professor Zhang Yukun of the School of Architecture of Tianjin University has independently built a real-world three-dimensional image platform for the entire Great Wall, and 5,500 kilometers of Great Wall content (including secret doors) have been digitally presented in high definition, allowing tourists to get an immersive viewing experience without going to the Great Wall.
The 3D image platform of the Great Wall has precipitated the team's exploration and accumulation of the protection of the Great Wall over the years, and this valuable digital asset formed by modern technical means has brought the sleeping Great Wall to life.
Ancient military wisdom has long been neglected and misunderstood
The so-called "secret door", as the name suggests, is a door that is disguised and hidden and not made public. Its setting is for offensive and defensive needs. In terms of its scale, the gate of the Great Wall can be divided into three categories, of which the larger one is "Guan", which belongs to the important geographical gateway connecting the outside and the interior of the country in ancient times, and is generally equipped with heavy troops to gather and defend, such as Juyong Pass, Huangya Pass, etc.; Medium is "kou" (side mouth), such as Mutianyukou, Zhangjiakou, etc.; The smallest is the "secret door".
The maintenance of the nomadic economy in the north depended to a considerable extent on plundering or trading in the agrarian rich areas, and constant harassment and irregular market opening made ethnic relations inside and outside the Great Wall extremely uncertain. The purpose of repeatedly building the Great Wall by many Central Plains dynasties is to control the movement of materials, information, and personnel on the geographical aperture of the border, and to achieve an effective balance and countermeasure in military, economic, and resource aspects, so as to ensure the overall stability of the economic interlaced zone.
The secret door plays a multi-faceted role in the interaction of border ethnic groups, deeply participates in the development of grassroots society in the border areas, and affects the direction of political and economic relations inside and outside the Great Wall. The ancient military wisdom contained in the secret door and the corresponding engineering planning and construction ideas have an important impact on the economic activities inside and outside the Great Wall, and are the wisdom and culture left by the ancients.
Although the scale and passability of the facilities of the secret gate are lower than those of the Great Wall's "pass" and "entrance", it is still officially opened, and there is a clear distinction from small ancillary facilities such as "water gate" and "water mouth".
"Due to historical reasons, there are few remains of secret doors on the Great Wall, and they are scattered in the shadows, unknown and even ignored and misunderstood." Li Zhe, a team member, distinguished researcher and doctoral supervisor of the School of Architecture of Tianjin University, said.
The three-story enemy building of the Great Wall of Yingpan Village, Gubeikou, Luanping County, Chengde, was reported as a special enemy building type in 2012, but the role of its western cave entrance has not been further studied;
A pair of blocked coupon holes on the outer branch wall of the Jinshanling Great Wall in Luanping County was identified as a "wall arrow window" in 2013.
According to reports, the "National Ming Great Wall Resources Survey" project carried out since 2007 has carried out positioning, statistics and basic measurement of various site facilities, but the secret door has not been fully revealed as an independent type, some provinces and regions have been registered as "convenience gate", and some lots are classified as "water gate".
More than 130 secret doors have been identified, concentrated in Beijing, Tianjin, Hebei and Jin
The Great Wall is an ancient Chinese military fortification and a symbol of the splendid civilization of the Chinese nation. Due to the twists and turns of the Great Wall built by successive dynasties, how to make scientific and accurate measurements for the Great Wall has become a very challenging problem.
Zhang Yukun's team started the research on the Great Wall in 2003, began to apply UAV low-altitude information acquisition technology in 2004, and launched the "Great Wall Full-line Real 3D Image" acquisition project at the end of 2018. Over the past four years, the team has crossed 10 provinces and regions to carry out digital mapping without blind spots along the entire Ming Great Wall. They used more than 2 million photos taken by drones to produce a three-dimensional database with average centimeter-level accuracy, which clearly presented the structure inside and outside the Great Wall to the world, allowing the secret door family to "live".
The entrance to the trap is generally 0.7 to 1.6 meters wide and 1.5 to 2.5 meters high, of which the narrowest can only accommodate a single person and the widest can be used by horses to travel; Structurally, trapdoors can be divided into stone or wood beams and brick or stone arches.
Because the secret door should take into account the traffic efficiency and safety concealment, it is divided into two categories: direct and non-direct; And combined with the main wall, support wall, enemy building, Dengcheng Road, horse market and other facilities, derived a rich secret door traffic mode.
The pass-through trapdoor has the highest efficiency, taking into account rapid sneak attacks and daily non-military activities. However, the direct doorway lacks a means of deterrence, so it is often opened near the enemy platform/enemy building, and connected with the city road, which is convenient for officers and soldiers on the top of the wall or in the enemy building to monitor and inspect.
Up to now, more than 130 physical remains of the secret door have been identified, most of which are brick and stone sites, concentrated in Jizhen, Zhenbao Town, Xuanda and other sections of Beijing-Tianjin-Hebei. The Qingming Great Wall in Shaanxi-Gansu-Ningxia is not easy to preserve due to the rammed earth structure, and only 2 secret doors have been found so far; In addition, relying on ancient public opinion maps, 41 secret doors in the west were sorted out.
Trapdoors generally lack their names and plaques, and about half of the 220 identified remains of trapdoors belong to this category. In the past, the term "convenience door" was used to refer to such nameless doorways or small openings, which is inaccurate. As the official title in ancient texts, "secret door" can better express its hidden properties in form and function.
Non-straight-through trap doors are the most concealed and changeable, but they are all staggered through the inside and outside openings to achieve the purpose of non-straight. The wall top, the wall inside the turning type, the wall top turning type trap door uses the two inner and outer climbing roads and the middle section of the wall roof to pass through, usually close to the enemy building to facilitate surveillance. When the enemy building is located in the middle of the two dengcheng roads, the flow line of entry and exit of the top of the wall must pass through the enemy building, which is more deterrent. The in-wall turning trap door obtains a similar deterrent effect by closing the narrow turning doorway.
The non-direct secret doors opened directly on the facades of the enemy building are higher and safer: "The platform is built under the platform, the door is moved up, and a ladder is placed outside, and the ladder is removed when it is captured, which seems to be stable." "Although the ladder is safer, it is inefficient, and for this reason, there is also the practice of opening secret doors on one or both sides of the enemy building.
The "true and false secret door" of Beijing Miyun Tianyun Mountain consists of a pass-through coupon cave secret door and a blocked secret door inside the door, and the two doors are only 10 meters apart. The false secret door doorway does not lead directly, but a door wall is set up inside the doorway, and if the enemy army mistakes the entrance hole, the defender can climb the wall from the inner steps to defend it condescendingly, or even climb down the door wall to meet the "real" secret door next to it.
"In addition to changing the flow line of the doorway, the location of the opening of the hole is also an important part of improving the safety and concealment of the secret door. Ming Dynasty border craftsmen also consciously used the shadowy corners of walls or enemy buildings to cover the entrance to the secret door. In addition, in order to pursue good concealment, the enemy building door hole type secret door generally chooses to open on the side and back façade. Li Zhe said.
The rigor and ingenuity of ancient Chinese military engineering design is concentrated in the small but precise type of city defense facilities such as secret doors, and the location, style and group cooperation of secret doors are the optimal solution obtained by balancing safety, economy and use efficiency under the premise of terrain conditions and border needs, which is a vivid embodiment of the idea of "adapting measures to local conditions" of traditional architecture.
According to Li Zhe, the total number of original secret doors of the Great Wall of the Ming Dynasty should significantly exceed the current record. There are also a considerable number of hidden door remains buried under the collapse of the wall or covered by plants, and they will be found in the subsequent archaeology of the Great Wall and the construction of national parks.
Over 2,000 years! Tumen appeared in Qinhuangdao
"In recent years, we have built the 'family map' of the secret door for the first time in the investigation of the entire line of the Great Wall of the Ming Dynasty." Li Zhe revealed that the section of the Great Wall where Tumen was found was located near Qinhuangdao in Hebei Province and was an important part of the Great Wall of the Ming Dynasty.
Tumen as an ancient defense facility, as early as more than 2,000 years ago in the Spring and Autumn Warring States period there are similar facilities recorded, "Mozi Beitu" chapter made a special work on Tumen, since then, Tang, Song, Ming, and even Qing dynasty scholars have recorded, but there are few modern related research papers, and no corresponding physical objects have been found.
The Gate is the most secret exit of all the secret doors, and the outside is made of brick, which looks like the city wall from the outside, making it impossible for the enemy to distinguish. When the breakthrough door is not broken, it is completely hidden, and once it is necessary to send troops to defeat the enemy during the battle, the soldiers inside can quickly smash the surface wall, just like the egg breaks the shell, the soldier breaks through the wall, pinches the enemy on the side, and can even push the artillery out of the breakthrough door to repel the enemy.
"Although Tumen is a small facility on the Great Wall, it reflects the inheritance of the wisdom of the ancients more than 2,000 years ago." Li Zhe said that this cultural inheritance is very vivid. Other members of the secret door family also hide the wisdom of the ancients, for example, there are real and false secret doors that deceive the enemy, the two are about 30 meters apart, if the enemy enters the wrong way, it is to catch turtles in the urn; Some secret doors are disguised as arrow windows; Some are so hidden that they are imperceptible, the scale is small, only one person can bend over and pass sideways, and it is very tortuous.
"Doorway blocking trap doors are divided into two categories: outer blocking type and door internal blocking type. The outer sealing type secret door is what Mozi calls the 'protruding door'. Li Zhe introduced, "The city is a secret door... Do not wear five or six inches. Or in the middle of the night, when the enemy first arrived, the camp was undecided, and the elite horse jumped out of the sudden gate, striking him unprepared, and attacking him unexpectedly. That is, at the hole outside the secret door, a half-brick thick sealing wall is kept at the level of the city wall, which is flawless in peacetime, but soldiers can break through the wall and carry out surprise attacks in wartime.
"The stone city of the three passes, can be ten thousand people, open the gate for night attack", the ancient military wisdom contained in the gate is inherited by the Ming Great Wall, but its outer blocking layer structure is fragile and difficult to preserve, at present, there is no trace of the three gates, and the occasional relics in other sections are also easily mistaken for broken walls and ignored or "destructive repairs".
More than 2,000 years ago, the "blocked passage" reappeared
"The secret gate of the Great Wall embodies the simple dialectical way of thinking and profound and broad planning ideas of ancient China, and the excavation of the gate as an example has made the military wisdom of the Mozi era have a physical inheritance, reproducing the 'blocked passage'." Recently, Zhang Yukun, a professor at the School of Architecture of Tianjin University, said in an interview with reporters.
The secret door opened up a new understanding of active defense, breaking the limitations of the previous understanding of the Great Wall as a conservative and closed symbol. The widely distributed, functional, and complete secret door family and the ingenious design behind it show that even in the construction of the grand and cumbersome military engineering system, the ancient Chinese still insisted on meticulous grasp of the political situation, the laws of war, and the defense environment, and implemented them in the precision engineering design, showing amazing overall planning ability and rigorous practical spirit.
At present, one of the core tasks of the construction of the Great Wall National Cultural Park is to make the historical sites of the Great Wall "live", promote the restoration of historical scenes such as the defense, defense, and trade of the Great Wall, serve the display of site landscape resources with more depth of knowledge and perceptibility, and enable the Great Wall National Park to perform its social, cultural and educational functions at a higher level.
The construction of the Great Wall National Cultural Park puts forward higher requirements for the depth and breadth of the excavation, interpretation and utilization of the Great Wall cultural landscape resources. The in-depth analysis of the function, type and distribution of the trapdoor is helpful to interpret the construction intention and operation mechanism of various facilities and the entire defense system of the Great Wall, leverage a series of new site value cognition from an overall perspective, and lead the in-depth excavation of the cultural landscape resources of the Great Wall.
The secret door may seem trivial, but it can lead to a multi-level historical understanding of the Great Wall. This shows that whether it is the management of the Great Wall cultural preservation or the construction of the cultural park, we should maintain awe for the details of the site, and conduct comprehensive and systematic observation and research on the remains of the Great Wall.
The functional use of the Great Wall secret door
Adjacent to the closing door and the side wall. The methods of responding to the main gate include the use of long-range firearms bombardment or the form of surprise attacks and interceptions. Gates and mouths are generally located in important geographical apertures such as river valleys and rivers. Secret doors are often opened at the height of the two wings, and when the pass is attacked, it is used to send troops to help, "each rushing mountain beam has another invincible general cannon, one from each beam... The thief was on the nearest stage, regardless of the host and guest, and allocated ten troops to help put the throne outside the wall. Each place located in the lower wall of the near platform opens a secret door, one is convenient for putting the hammer, and the other is convenient for the army to guard the slope."
The relationship between the secret door and the main gate reflects the military strategy of "strange and positive". Sun Wuyu said: "Those who can be defeated by enemies are also wonderful." "Qi Zheng Xiangsheng is considered by successive generations of soldiers to be a necessary guarantee for victory in battle. In the description and interpretation of the secret door in important military theoretical works such as "Mozi", "Divine Mechanism Enemy Taibai Yin Jing" and "Wu Beizhi", Qi is the source of consistent military thought, reflecting the military strategy of the ancients to actively defend.
Sentinel holes are provided. The secrecy of the traffic aperture has a bearing on the safety of intelligence personnel and the information they exchange; "(the enemy) every few days before the invasion, the advance sentry blocks block our outpost, repeatedly leaving no report on the imminent period." Therefore, the scattering, convenience, and secrecy of the secret door should be an inevitable requirement for the aperture of the outpost, and all kinds of sentries must undergo strict examination before entering and leaving. The return report must be verified by the secret door, and it is not allowed to enter the city without permission, and the home entrance is close from time to time, and the supply and leakage", and the evasion of one's own personnel in the sentinel operation also shows the necessity of the secret door.
Multiple non-military uses. In addition to military functions, the secret door is also responsible for allowing access to facilitate farming, wood harvesting, trade, exchanges, disaster prevention and other tasks.
In the middle and late Ming Dynasty, in order to alleviate the contradiction between land annexation and unclear tax responsibilities, the scope of tuntian was generally extended to the outside of the border, and "the leading officer was originally forbidden to go out of the border without authorization, so that he could not cultivate." He Wu Jian built a secret door in the land near the border area, or the water of the canal or the water of the mountain, and listened to the reclamation and cultivation of the residents nearby, and each of the generals inspected the army and set up a sentry to detect, and when the police converged, the agricultural gap was recovered." It can be seen that the secret gate of the Great Wall has become the main communication hole for military and civilian farming.
The continuous development of border land for more than 300 years in the Ming Dynasty also caused the continuous deterioration of the natural environment along the Great Wall, so that it reached the level of depletion of grass and tree resources at the end of the Ming Dynasty. "On the west side of Xuanda Mountain, the trees outside the wall are gloomy and the grass is dense, while inside the wall are the ochre soil of Tongshan Mountain, a flat sand, three points of grass, and a hundred dollars of firewood, so it is also very expensive." It is an important source of building materials for the local and even Beijing divisions, and it is also a means of livelihood for the poor border army, and it is also conducive to monitoring the enemy's situation, obtaining official acquiescence, and using secret doors as the core carrier.
Border market trade. After the Longqing collegial discussion, along the Great Wall, the city (horse market), a large number of secret doors were used as trade ports, "each with cow and sheepskin, with a notice to the generals, listening to the secret door, military and civilians can distribute goods and trade", reflecting that the secret door from behind the background of the grassroots defense tunshu into the front of the official political and economic interaction between Ming and Mongolia, has become the standard configuration of the horse city building. The choice of a trapdoor rather than a higher-level gateway as a cross-market hole indicates that its shape is suitable for horse market trading. For example, the secret door unearthed in 2004 is 1.74 meters high and 1.67 meters wide, which is similar to the scale of the secret door in Xushi Louma City, Qingshuihe County and Ninglou Ma City, Ninglubao Town, Zuoyun County, which can not only lead horses and packs through, but also facilitate opening and closing control and customs inspection at any time. The Great Wall Horse Market is usually composed of facilities such as the Horse City Fort, the Secret Gate, the Inspection Platform, and the Wengcheng to control the potential market grabbing and rioting behaviors in the bomb market. Both the Ming and Qing Dynasties implemented strict border prohibition policies, but all sections of the Great Wall and various types of secret doors have always been the spatial carriers and key nodes of official or unofficial trade activities, and the universality of border trade functions has long exceeded its original military use.
Use of political interactions. The main gates of the Great Wall in various places are often "not opened" under the national policy of border prohibition, so that the secret door replaces the main gate for political contact activities. "More than ten horses to get rid of the recovery rate, the secret gate of Ningyuan Fort in Yixuan Mansion, call for the incident, and save the knife to swear to Tonggong City." Not only do tokens interact, but nomadic tribes and armies can even use secret doors to achieve "harmless passage".
Some secret doors located on the mountainside are also called dry doors, because the main gate is easily washed away by torrential rain and flash floods, and the secret door can replace the main gate during the maintenance period. In addition, some secret doors are mistakenly classified as water gates, because of their multi-functional properties, usually as secret doors, in the rainy season to take into account drainage, so the use of secret doors is very wide.
The secret door may seem trivial, but it can lead to a multi-level historical understanding of the Great Wall. It shows that whether it is the management of the Great Wall cultural preservation or the construction of the cultural park, we should maintain awe for the details of the site, and base on the comprehensive and systematic observation and research of the remains of the Great Wall.
Inherit ancient Chinese architecture, military and political wisdom. The history of the secret door continued from the Spring and Autumn to the Ming and Qing Dynasties, and its architectural form and military ideas were passed down through the generations. The concept of active defense and the simple dialectical idea of "strange and righteous" are still active in the current Chinese cultural environment.
As a small site in the Great Wall site, the design of the secret door engineering still has strict control over details. Its specialized and systematic development for different functional scenarios reflects the cold and profound understanding of the laws of war and the wisdom of micro-military engineering, and is a concentrated embodiment of the cultural characteristics of the Chinese nation of unity of knowledge and action, pragmatism and rigor, love and equality.
As a grassroots Kongdao function to maintain the order of economic and cultural exchanges in the Great Wall area, the secret door was still continued until the Qing Dynasty, "the envoy Jinglin, the national tribute, the past letter and accommodation, the route of the secret door, and the business travel also came and went, and then became the Kongdao".