How about building a border defense in the early Ming Dynasty?

1368, the peasant emperor Zhu Yuanzhang proclaimed himself as emperor in Nanjing, with the title of Daming, with its capital in Tianfu and the title of Hongwu, and established the Ming Dynasty. Zhu Yuanzhang is Ming Taizu. Soon after, Zhu Yuanzhang ordered Xu Da, the founding military commander, and Chang Yuchun, the founding star, to carry out the Northern Expedition.

Beijing, the capital of the Yuan Dynasty, was captured, and the leader of the Mongolian and Yuan rulers fled to the north, ending the 89-year rule in the Central Plains, and China once again returned to the Ming Dynasty rule established by the Han nationality.

142 1 year, the Ming dynasty moved its capital to Shuntianfu, and Yingtianfu was renamed Nanjing.

It is said that at the beginning of the Ming Dynasty, the country was strong, but the Mongolian nobles Tatar and Wala who returned to Mobei grassland continued to harass and plunder in the south.

Therefore, in the early days of the founding of the People's Republic of China, that is, from 1368 to 1447, the Great Wall was built in Liaodong section of Ming Dynasty, as well as in the west and north of Daxing 'anling, Yinshan and Helan Mountains.

According to China's ancient books, the Great Wall project in the early Ming Dynasty was mainly based on the Great Wall of Northern Wei, Northern Qi and Sui Dynasties. "Smoke piers are built thick everywhere, with May grain and firewood crossbows stored on them, and a well is opened next to the pier ..." "From Chang 'anling West to Ximalin, build stone walls and dig deep ditches", that is, build smoke piers, beacon towers, garrisons and trenches, and change earth walls into stone walls in some areas. The focus of this renovation is the Great Wall from northwest Beijing to Datong, Shanxi, and the border pass from Shanhaiguan to Juyongguan, Hebei.

For example, Juyongguan City is 1368 "General Xu Da built a city across two mountains". Jiayuguan is 1372 "Shengfeng patrols the west of the river, and the first pass is the extreme border defense".

1373, "Zhao Shanxi stays between Yanmenguan, Taiheling, Wuwu and Shuozhou, and all 73 passes are kept".

1374 yanmenguan city; Gubeikou Guancheng, built in 1378 Xudashanding, is named Yingcheng. 138 1 year in the first month, General Xu Dafa, Yanshan and other guards were 5 1000 people, and Xiu Yongping.

There are 32 passes such as Jieling, and only the Acropolis is built, which is called Shanhaiguan. Piantouguan is a tucheng built in 1390. Famous passes such as Zijingguan and Daomaguan Shangcheng were built in Hongwu period. Huangyaguan in Tianjin and Mutianyu in Beijing were built in Yongle period, Dushi Pass in Hebei was built in 1426, and Zhangjiakou Fort in Hebei was built in 1429 ... It was the construction of these passes that formed the center and basic skeleton of the Great Wall in the late Ming Dynasty. These passes and Great Wall sites built in the early Ming Dynasty have been preserved until later. Among them, the earliest built Juyongguan Great Wall site is located in a canyon 20 kilometers north of Changping, Beijing, with a length of 15 kilometers, 60 kilometers away from Beijing and 20 kilometers away from Badaling Great Wall. This is an important pass of the Great Wall, and the terrain is dangerous. The canyon where Juyongguan Great Wall is located belongs to the mountainous area where Taihang Mountain is located, and the terrain is extremely dangerous. As early as the Spring and Autumn Period and the Warring States Period, the State of Yan had to control this mouth, calling it "Juyong Plug"; During the Han Dynasty, Juyongguan City was quite large. During the Southern and Northern Dynasties, Guancheng architecture was connected with the Great Wall. After that, the Tang Dynasty, Liao Dynasty, Jin Yuan and Juyongguan Canyon were all related to the construction of the city. The defense system of Guancheng consists of five defense lines from north to south: Chadao City, Juyongguan Town, Shangguan City, Guanzhong City and Nankou, with Juyongguan as the command center.

Long Weiqing is responsible for guarding the city, equipped with helmets, armor, spears, bows, arrows and other ordnance and firearms. Guancheng not only has a complete building, but also has official offices, warehouses, libraries, hangars, temples, Confucianism and other related facilities with profound cultural connotations.

It is said that the emperors of the Yuan, Ming and Qing Dynasties all passed through here, which is unique and unparalleled as a political position and military fortress. Juyongguan not only has dangerous terrain, but also has pleasant scenery. After entering Guangou from the south entrance of Guancheng, the mountains on both sides of the strait overlap, the streams are gurgling, the vegetation is lush in spring, summer and autumn, and the flowers and weeds are lush, which looks like blue waves. As early as the Jin Dynasty, it was listed as one of the eight scenic spots in Yanjing, which has been passed down to this day.

Jiayuguan Great Wall is located in the southwest corner of Jiayuguan, named after it was built at the foot of Jiayuguan Mountain. It was the end of the western end of the Great Wall in Wan Li in the Ming Dynasty. The Guancheng plane is trapezoidal, covering an area of about 33,500 square meters, with a total length of 733 meters and a height of 1 1.7 meters.

The tower is symmetrical from east to west, three rooms wide and surrounded by cloisters. The top of the three-story rest mountain is 17 meters high, which is magnificent. There is a watchtower at the four corners of Guancheng, which is two stories high and looks like a bunker. From a distance, you can see the scenery outside the village.

The city walls on both sides of the city pass through the desert Gobi, connecting the Great Wall hanging in Montenegro in the north and the first pier in the world in the south. It is the westernmost part of the Great Wall in Wan Li in the Ming Dynasty. Known as "the first pass in the world", it has been the first pass in Hexi since ancient times.

Jiayuguan Great Wall consists of three lines of defense, namely, inner city, outer city and moat, with overlapping defenses, forming a military defense system of 2.5km, 5km,15km, 50km, one city and one defense.

Guancheng is dominated by the inner city, with a circumference of 640 meters, an area of 25,000 square meters and a height of nearly 1 1 meter. Rammed with loess, covered with bricks on the west side, majestic and solid.

The inner city has east and west gates, and the east gate is Guanghuamen, which means that purple gas rises and Guanghua shines; Ximen is the gate of softness and distance, which means softness and distance, and stabilizes the western border.

There are urn paddocks outside the two doors, and there are 14 watchtower, watchtower, watchtower, attic and gatehouse on the inner wall of Jiayuguan. Jiayuguan Guancheng is the most intact one among many Guancheng in the Great Wall.

The Great Wall of Yanmenguan is located on the mountainside of Yanmen, 20 kilometers northwest of Daixian County, Shaanxi Province, and it is also called "three passes" with Ning Wuguan and Pianguan. The nearby peaks are staggered, steep and gloomy, and the middle roads are vertical and horizontal, winding and passing through the city, which is extremely dangerous for successive dynasties.

In history, Wild Goose Gate is a pun. The two customs are 5 kilometers apart, and the ridge is connected by the Great Wall, which is Dongguan and Xiguan.

"Biography of Mu" records: "In the Sino-Japanese War of 1894-1895, the emperor moved westward, which was the gateway to danger." Zhou Muwang was the fifth king of the Western Zhou Dynasty, belonging to the early Western Zhou Dynasty. According to this calculation, there was Yanmenguan around 1000 BC.

Yanmenguan, rebuilt in the Ming Dynasty, is the East China Pass, the gateway given to mankind by nature, and has broken through the mountain barrier between the Great Wall and the south of the Yangtze River. It has played an important role in human history and occupied an important historical position.

Yanmenguan in Tokyo consists of Guancheng, Wengcheng, Dongcheng, Xicheng and besieged city, with Guancheng as the main city. Natural barrier gate, smoke building, geographical gate and Yang Liulang Temple are set up in turn along Guguan Road. The walls on the east and west sides of Guguan Road are divided into Dongcheng and Xicheng. The buildings in Xicheng District are related to Guanbing Plate and Wild Goose Pagoda. North of Guancheng is Wengcheng, where there is a martial arts temple and a stage. Wengchengmen, also known as Xiaobeimen, has a gatehouse. The southern end of the besieged city is divided into east and west wings, extending northward to the bottom of the valley, and there is a building at the Ningbian gate of the besieged city.

There are parting tablet pavilions, Baotu Spring and Quanting in the besieged city, and the outside of the wall is connected with Lianguan Road, Guan Qiao, a stone arch bridge. There are 3 large stone walls and 25 small stone walls outside the customs.

In front of the pass, there are successively Changping Bridge Monument, Horse Worker Killing Tiger and Horse Cemetery, Nandao Monument Pavilion, Guanling, Yunjiquan, Jiulong Pavilion, Yanjing Square and Lime Temple. Guguan Road runs from north to south, south to Nankou and north to Guangwuguan, with a total length of more than 20 kilometers.

Yanmenguan is the oldest and most important pass in the Great Wall of Wan Li. The "Catalogue" records: "There are nine sights in the world, and the wild goose gate is the head". The east gate of Yanmenguan is closed and inlaid with couplets. "Running on three sides is unparalleled, and the nine races are the first level."

"Two passes, four passes and eighteen passes" is the unique military defense system of Yanmenguan. Two customs, namely Dongguan and Xiguan; Four mouths, namely Taihe Lingkou, Nankou, Baicaokou and Guangwukou; Eighteen passes, namely Shuiyu, Huyu, Malan, Yueru, Xiaoshi, Dashi, Beilou, Tai 'an, Tuancheng, Pingpunishment, Taihe, Shuiqin, Suspension Bridge, Miaoling, Shi Xia, Yangwuyu, Xuangang and Lubankou.

Gubeikou is located in the southeast of Gubeikou Town, Miyun, Beijing. It is the Great Wall fortress between Shanhaiguan and Juyongguan. It consists of Wohushan Great Wall, Panlongshan Great Wall, Jinshanling Great Wall and Simatai Great Wall.

In 555, the Northern Qi Dynasty built the Great Wall from Xihe to Shanhaiguan, with a total length of 1500 km. Among them, Gubeikou is the focus of fortification. Jin and Yuan Dynasties added this pass. In the Ming Dynasty, Guancheng, large and small gates, beacon towers and two gates were built. A door is located at the gate of the Great Wall, called "tiemenguan", and only one rider and one car are allowed to pass through. A gate is located on the Chaohe River, called "Watergate Pass", where remains are preserved. Wangjinglou is the highest point of this section of the Great Wall, 986 meters above sea level.

Gubeikou Ming Great Wall is the first military defense line in the northern part of Gubeikou, the strongest and most magnificent section of Wan Li Great Wall in Ming Dynasty, and the only section that completely preserves the original appearance of the most essential part of the Great Wall in Ming Dynasty.

Badalizi Great Wall is located on the west side of Xishan Mountain in Gubeikou, Miyun County, starting from Xigou in the east and reaching Longtangou in the west. It is the Wild Great Wall that few people go to. It is said that standing on the western hill of Wohu Mountain and looking west, you can see that there are eight watchtowers on this mountain, hence the name.

It is said that it is eight buildings. In fact, from Xigou to Longtangou, there are 13 hollow brick buildings, a solid rubble pier, a completely collapsed brick abutment and a relatively intact brick abutment.

The first five watchtowers are all on the rising ridge with continuous side walls in the middle. Among them, the first and second floors were seriously damaged, the third floor has collapsed, and some towers remain on the fourth floor, but the wall on the north side of the watchtower has collapsed. The fifth floor is well preserved, but the arrow window has been broken into a big hole. The fifth to seventh watchtowers have gentle mountains and obvious mountain roads.

The sixth and seventh floors collapsed. The seventh floor is the commanding height in this area, about 8 10 meters above sea level. Looking west from here, you can see a panoramic view of the mountains in the west. The eighth floor covers the valley not far below, followed by the ninth and tenth floors connected by ferocious ridges. Finally, 1 1 building, 12 building and 13 building are all built on the hill facing 10 building across the ditch in the southwest, and the distance between 12 building and 13 building is only tens of meters.

Huangyugou Great Wall is a short-lived Great Wall in Xigou, Gubeikou. Not only is it steep and beautiful, but because it has not been repaired, it is hidden in the mountains, and the lying ruins have a desolate beauty.

Broken, old and simple masonry stretches over mountains, and the natural beauty of desolation and uncut can make people feel the indomitable character of Jinge Iron Horse for thousands of years. The most distinctive feature of Huangyugou Great Wall is the circular watchtower.

The watchtowers on the Great Wall are mostly square or rectangular, and the circular watchtowers are basically concentrated on the side of the sample, that is, the Shuitou Great Wall Line, which is rare in Miyun and Huairou lines. Such a well-preserved circular watchtower is very rare.

Wohushan Great Wall is located in Gubeikou Town, Miyun County, the western section of Gubeikou Great Wall System, with a total length of about 4.8 kilometers, 134 towers, the highest elevation of 665 meters, and the mountain is steep, so it is magnificent.

The view of the top of Wohu Mountain is wider than that of Simatai Great Wall, surrounded by mountains in the north and rivers in the south. The East-West Great Wall is undulating and unique.

Climb the main peak and overlook: Wuling Mountain in the east, Ant Ridge in the west, Miyun Reservoir in the south and Taoshan in the north.

There are dozens of cultural relics near Wohu Mountain, such as Gong Ling Temple, Taiping Temple, tiemenguan, Wanshou Mountain, Wild Boar Ridge, Lvzu Temple and Liulinying.

Wohushan Great Wall is a masterpiece in the architectural history of the Great Wall because of its age, variety, ingenious layout and complete facilities.

There is the only sister building of Wan Li Great Wall, the longest Shuiguan Great Wall, and the extremely rare flat building, round building, half building, double crib and "knife handle building". There is also a spectacular "Great Wall Knot" composed of the Northern Qi Great Wall, the Ming Great Wall, the Ming Great Wall ruins and the Great Wall sub-cities.

All these constitute the rare and precious cultural relics on the Great Wall of Wan Li.

The Great Wall of Wanshou Mountain is 780 meters long, with 7 watchtowers, Wohushan section 1.6 kilometers, and 9 watchtowers. The mountain is steep and the watchtowers are dense. It is connected with Baduanzi Great Wall in the west, and locks the Chaohe River with Panlongshan Great Wall in the east, which is called "Shi Jing Lock Key" in ancient times.

Most of the Great Wall here is built on steep peaks and cliffs. Magnificent, magnificent, the trend is full of changes and rhythm. In some places, it is almost vertical, while in others, it is almost suspended and dangerous.

Panlongshan Great Wall is located in Gubeikou Town, Miyun, and is known as the gateway of Yanjing. It is located between Simatai Great Wall and Wohushan Great Wall, 0/00 km away from Beijing/KLOC. It is the only ancient Great Wall in China that has not been artificially repaired to maintain its original historical features. Besides the Great Wall in Ming Dynasty, Beijing also has the oldest Great Wall in Northern Qi Dynasty.

Panlongshan Great Wall is the Great Wall with the most wars in history. Its relative height is not high, about 150m, and the length of the climbable Great Wall is about 5km. The famous watchtower "General Building" has 22 doorways, which are rare and magnificent, and keep the original appearance. Wulituo Great Wall is at the end of Jinshanling Great Wall, which is actually a part of Gubeikou Great Wall, but it is the best angle to see Wulituo Great Wall from the Sixth Eye Building of Jinshanling.

Jinshanling Great Wall is located in Luanping County, Chengde, Hebei Province, adjacent to Miyun, Beijing, and 130 km away from Beijing. It was built under the leadership of Qi Jiguang, a patriotic general of Ming Dynasty, as the chief company commander of Zhen Ji Town. It is the essence of the Great Wall in Wan Li, and is known as "Wan Li Great Wall, the unique golden mountain". Barriers, writing bricks and stones are the three wonders of Jinshanling Great Wall, and they are known as "a paradise for photographers".

Jinshanling Great Wall is located at the intersection of Beijing, Tianjin, Liaoning, Mongolia and other places, spanning the Yanshan branch at the junction of Luanping County in Chengde, Hebei Province and Miyun in Beijing, connecting Simatai Great Wall in the east and Gubeikou Great Wall in the west.

This section starts from Gubeikou, a historical pass in the west, and ends in the towering wangjinglou in the east, with a total length of10.5km.. There are 5 passes, 67 watchtowers and 3 beacon towers along the line, which are famous for their broad vision, dense watchtowers, strange landscape, exquisite architectural art, sound military defense system and well-preserved.

Jinshanling is 700 meters above sea level. The mountains in the north are like waves, the Simatai Reservoir in the east is like a mirror, and the Miyun Reservoir in the south is like blue waves. The Great Wall is surrounded by mountains and dangers, with ups and downs between mountains and rivers, and the situation is extremely magnificent.

In particular, the watchtowers here are dense, exquisitely structured and various, which are incomparable to the Great Walls such as Badaling, Shanhaiguan, Jiayuguan and Juyongguan, and are one of the tourist attractions being developed by the Great Wall of Wan Li.

Jinshanling Great Wall is winding and winding, with wide vision, dense watchtowers and magnificent scenery. There are mountains and forests inside and outside the Great Wall. Spring, summer, autumn and winter are suitable for hiking and photography.

Simatai Great Wall is located in the north of Simatai Village in Gubeikou Town and east of Jinshanling Great Wall. The city wall is built on the mountain and is famous for its strangeness, uniqueness and danger. Simatai Reservoir divides the Great Wall into east and west sections. There are 16 enemy towers in the eastern section and 18 in the western section.

Enemy towers are dense, diverse in shape and different in structure. The average distance between buildings is only140m, which is extremely magnificent. At the peak of the Great Wall in the eastern section, there are two most prominent watchtowers, namely the Fairy Pagoda and the wangjinglou. Wangjinglou, in particular, is built on a steep mountain peak at an altitude of 1000 meters, with excellent scenery and overlooking Beijing.

Of course, the eight Lizi Great Wall, Huangyugou Great Wall, Wohushan Great Wall, Wanshou Great Wall, Panlongshan Great Wall, Wulituo Great Wall, Jinshanling Great Wall and Simatai Great Wall located in Gubeikouguan Great Wall were all built at the same time, but their sites are collectively called "Gubeikouguan Great Wall". In addition to Gubeikou Great Wall, Shanhaiguan Great Wall built in the early Ming Dynasty is also famous. Shanhaiguan Great Wall is 26 kilometers long, mainly including: Laolongtou Great Wall, South Wing Great Wall, Guancheng Great Wall, North Wing Great Wall, Jiaoshan Great Wall, Sandaoguan Great Wall and Jiumenkou Great Wall.

This section of the Great Wall consists of seven castles: Guancheng, Dongluo, Xiluo, Nanyi, Yi Bei, Weiyuan and Ninghai. The circumference of the city wall is about 4.8km, with a height of11.6m and a thickness of10m. The wall is tall and strong, which is very spectacular.

There are four gates in the east, west, south and north of the city. There are turrets in the southeast corner and northeast corner of the city, and there is a magnificent bell and drum tower in the center of the city. The entire Acropolis building is large in scale and the defense project is solid. Shanhaiguan was the product of the garrison system established in Ming dynasty, and the "reclamation system" and reform policy of Ming dynasty played an important role in the consolidation and development of Shanhaiguan. Among them, Guancheng Great Wall is the middle section of Shanhaiguan Great Wall, with a total length of about 7. 1 km, and its main line, namely the east wall of Guancheng, is about1.4 km long; The attached line is located in the west, north and south walls of Guancheng, with a length of about 3.4 kilometers.

Dongluo city wall is about 1.5km long, and Wengcheng city wall is 823m long. There are also six enemy towers and two towers on the main line, including Zhendong Tower, Lulin Tower, Muying Tower, Xinlou, Jingbian Tower and Weiyuan Hall. Attached lines include Guancheng City Wall, Dongluo City Wall and Wengcheng City Wall.

The Great Wall in the north wing starts from Beidou Peak in the south and ends at 10 station at the foot of Jiao Shan in the north, with a total length of about 3 kilometers. The Great Wall of Jiao Shan mainly includes Hanmen 10 Platform, Hanmen Pass, Jiao Shan Enemy Platform and Yuecheng. Sandaoguan Great Wall is mainly composed of the city wall, Taoyuan East/KOOC-0/3 enemy platform, Sandaoguan, Lanshiguan, Tangmao/KOOC-0/6 enemy platform, Jianshan West/KOOC-0/7 enemy platform and Jianshan East/KOOC-0/8 enemy platform. Jiumenkou Great Wall mainly includes Wudaolou, jujube hill and Jiumenkou.

Laolongtou Great Wall is the end part of the Great Wall that enters the sea, and it has the reputation of "the soul of China". Located about 4 kilometers south of Shanhaiguan, it connects the Great Wall in the north and enters the Bohai Sea in the south, which is the starting point of the eastern end of the Great Wall in Wan Li in the Ming Dynasty.

The Old Dragon Head Great Wall, referred to as the Old Dragon Head for short, is composed of Shicheng on the sea, Lu Jing 1 enemy platform, Wang 'ai No.2 enemy platform, Nanhai Kouguan, Chenghailou, Ninghai Building, Ninghai City and Binhai City Wall. Built in 138 1.

At that time, there was a stone city 23 meters into the sea, and Chenghai Tower was built on the wall. It was destroyed by soldiers, leaving only a rotten wall facing the sea.

Since the establishment of Shanhaiguan, frequent business contacts and active economic and trade activities have played an important role in developing friendly exchanges among all ethnic groups, promoting economic and cultural exchanges, defending the capital and consolidating the rule of the Ming Dynasty. No matter in scale, layout or structure, Shanhaiguan is rare in the history of ancient architecture in China. It is also the essence of the Great Wall in Wan Li, and a rare masterpiece in the treasure house of ancient urban architecture in China.

Piantouguan, built after Bishan Pass, is located on the Yellow River in Pianguan County. It is called "Three Pass" together with Ning Wuguan and Yanmenguan, and it is named "Piantouguan" because its terrain lies in the east and west.

The shape of Piantougou Guancheng is irregular, and the length from east to west is 1. 1 km. There are urn cities in the east, west and south gate. Masonry is laid at the height of 10 meter, and most of the masonry still exists from the south gate to the west gate. Most of the western and northern walls are rammed earth walls, while the eastern wall has been destroyed. In the Ming Dynasty, in addition to Piantou Pass, 22 cities were built along the Great Wall and important passages, including Hualin Fort, Laoniuwan Fort, Caoduo Mountain Fort and Laoying Fort.

Most of the side walls of these castles are now rammed earth, but they are located in the Hualinbao section on the bank of the Yellow River. About 30 kilometers of side walls are well preserved, all covered with bricks, towering above the river bank, which is very spectacular.

Tianjin Huangyaguan, rebuilt during Yongle period, is located in the mountains 30 kilometers north of Jixian County. Historically, there were 18 weidun in Jizhou city, and Huangyaguan was one of them and the most important pass. It was built in 556 and rebuilt in Ming Dynasty.

Malanguan, Zunhua County, Hebei Province in the east, and Huangyaguan Great Wall, the general pass in Pinggu, Beijing in the west, are part of the ancient Great Wall of China, with 66 towers, namely 52 enemy towers and 14 beacon towers, which are the military sites of JD.COM.

This is an important pass of the Great Wall in Zhen Ji Town in Ming Dynasty and the only pass in the county. The rocks on the cliffs on the east side of Guancheng are mostly yellow-brown. Whenever the sun sets, it is resplendent and magnificent, and it is known as the "yellow cliff at night", hence the name Guancheng.

Mutianyu Great Wall in Beijing, built at the same time as this Ming Great Wall, is located in Huairou District.

This section is connected to Juyongguan Great Wall in the west and Gubeikou in the east. The famous Great Wall landscape arrow buckle, horn edge and upside-down flying eagle are located at the western end of Mutianyu Great Wall, which are the essence of Wan Li Great Wall.

Mutianyu Great Wall is mostly built on steep cliffs outside, relying on the mountain to take advantage of the situation to control Eritrea. The wall is seven or eight meters high and four or five meters wide at the top. The building materials are mainly granite, which is majestic and solid.

Mutianyu Great Wall has low battlements on both sides of the wall top, which can repel the enemy from both sides, and there are horse pits on the outside, which makes the defense function more perfect. This is a major feature. On both sides of Mutianyu Great Wall, there are stacks with a length of1.67m, a thickness of1.33m and a height of 0.67m.. ..

The closed sides of Mutianyu Great Wall rise along the ridge and turn over with the mountain. The crenels in these areas are not rectangular, but serrated. The shooting hole is built under the crib. It is not a round hole, but a square hole with an arc top.

There is also a battery in a dangerous place. Mutianyu Great Wall also has a "sub-city". The so-called "supporting the city" means building a section of the Great Wall along the mountain ridge where there are high ridges inside and outside the Great Wall, with a length ranging from several meters to tens of meters, and building an enemy tower here, which the locals call "knife tower".

When the Mutianyu Great Wall was rebuilt in the Ming Dynasty, cribs were built on both sides of the top of the wall, and a new rolling stone mine cave was set up to attack and defend. The construction of a "knife handle building" can control the commanding heights and reduce the threat to the main city. Mutianyu Great Wall starts from the left side of Zhengguantai, turns over with the mountain, and rushes to the distance.

The Great Wall extends from the mountainside to the top of the mountain. After the enemy tower was erected on the mountainside, it suddenly turned down and back to the mountainside, up and down until it was more than 940 meters above sea level, and it circled a big bend like a horn, vigorous and powerful. People call it "the horn edge".

The Great Wall continues to extend from the "Horn Edge" and passes through a place called "Jiankou". It is a mountain peak with an altitude of about 1km, with steep sides. When building the Great Wall, you must pass through the broken ridge and steep cliff outside the hill, and you can't leave this commanding height outside. Obviously, it is impossible to use bricks and wood.

So the clever craftsman used two big iron beams to bear the load on the cliff, and then laid bricks on it. This method is extremely rare in the whole history of Great Wall construction.

On the east side of Mutianyu Great Wall, the Great Wall originally extended to the northeast along the mountain. However, at the watchtower, the section of about 1 1,000 meters was suddenly divided and took another road to the southeast. At the end of the mountain, it came to an abrupt end, and a very strong and magnificent watchtower was built at the end.

This section of the Great Wall is more than 1000 meters long and is called "the bald tail edge". In this way, the Great Wall has formed a landscape where the three Great Walls meet on the first floor and the dragon is seen on three sides.

On both sides of the Mutianyu Great Wall, there is also a section of the Great Wall called "Arrow Buckle" and "Eagle Flying Inverted". The walls are all built on bare cliffs. Most of the slopes of the Great Wall are about 50 degrees, and one section is close to 90 degrees, almost vertical, and the steps are only a few feet wide, so people who are not brave dare not step in.