Length According to historical documents, the Great Wall was built over 5,000 kilometers in two dynasties: First, the Great Wall of Wan Li, which started from Lintao in the west and went to Liaodong in the east, was built by Qin Shihuang; 2. The Great Wall of Wan Li, which starts from Hexi Corridor in the west and ends in Liaodong in the east, was built in the Han Dynasty and is above 1 Wan Li. These Great Wall sites are located in Beijing, Gansu, Ningxia, Shaanxi, Shanxi, Inner Mongolia, Hebei, Xinjiang, Tianjin, Liaoning, Heilongjiang, Hubei, Hunan, Shandong and other provinces, cities and autonomous regions/kloc-0. Due to the long history, most of the Great Wall in the early dynasties was incomplete, and the Great Wall built in the Ming Dynasty was well preserved. So people usually indicate the Great Wall, and the so-called length of the Great Wall also indicates the length of the Great Wall, starting from Jiayuguan in the west and reaching Yalu River in the east. National Cultural Heritage Administration and the State Bureau of Surveying and Mapping jointly announced on April 8, 2009 that the Great Wall of Ming Dynasty starts from Hushan, Liaoning Province in the east, ends at Jiayuguan, Gansu Province in the west, and passes through Liaoning, Hebei, Tianjin, Beijing, Shanxi, Inner Mongolia, Shaanxi, Ningxia, Gansu and Qinghai provinces/0/56 county, with a total length of 88,556. After passing through the trench of 359.7 kilometers, the natural natural barrier is 2232.5 kilometers. National Cultural Heritage Administration 20/kloc-0 was announced at the Juyongguan Great Wall in Beijing on June 5th, February. After nearly five years' investigation, the total length of the Great Wall in China was 21196.18km, which was distributed in Beijing, Tianjin, Hebei, Shanxi, Inner Mongolia, Liaoning, Jilin, Heilongjiang and Shandong. This is the first time that China has scientifically and systematically measured the total length of the Great Wall. In 2009, National Cultural Heritage Administration released the survey data of the Ming Great Wall for the first time. The total length of the Ming Great Wall in China is 88,565,438+0.8km. This investigation and appraisal of the Great Wall not only identified the length of the Ming Great Wall, but also carried out the investigation of the resources of the Great Wall in Qin and Han Dynasties and other periods. [1] How to build the Great Wall During the long history of China, many feudal dynasties built the Great Wall many times in order to consolidate their rule. Thousands of working people in ancient Qian Qian contributed wisdom and blood to it, making it a miracle of the world. Whether it is a dragon-like city wall, or a production process and a more scientific brick burning workshop. Therefore, the output of brick products has greatly increased, and bricks are no longer precious building materials, so the inner and outer eaves of many places in the Great Wall of Ming Dynasty are built with giant bricks. Under the condition of manual construction and manual handling of building materials at that time, it was not only convenient to build the city wall with bricks with small weight and the same size, but also improved the construction rate and level. Secondly, the gates of many passes are long-span arches made of blue bricks. Some of these blue bricks have been severely weathered, but the whole gate is still magnificent, showing the superb skills of building arches at that time. Judging from the architectural decoration of the Guanta Tower, many stone carvings and brick carvings are extremely complicated and elaborate, reflecting the artistic talent of craftsmen at that time. The city wall is the main part of the city wall, with an average height of 7.8 meters, and some sections are as high as 14 meters. Where the hillside is steep, buildings are relatively low.

Flat places are built higher; The key places are higher, and the general places are lower. The wall body is the main part of defending the enemy, with a relatively wide total thickness, a foundation width of 6.5 meters and an average floor width of 5.8 meters on the wall, so as to ensure that the two wagons run in parallel. The wall is composed of an outer eave wall and an inner eave wall, filled with soil and gravel. The cornice wall refers to the side of the skin wall facing the city. There are obvious points when building, which are generally 125% of the wall height. The separation of the wall can increase the width of the lower part of the wall, enhance the stability of the wall, strengthen its defensive performance, and make the outer wall magnificent. The inner cornice wall refers to the inner side of the outer skin wall, which is generally constructed as a vertical wall without obvious points. As for the thickness of the outer cornice wall, it is generally based on the wall thickness at the "crib". The thickness here is generally one and a half bricks wide, and it gets thicker as it goes down. Bricklaying method is mainly flat masonry. The structural content of the wall depends on the local climate conditions. Generally speaking, the construction methods of Wan Li Great Wall are as follows: 1. Rammed earth wall; 2. Adobe masonry wall; 3. Brick wall; 4. Masonry wall; 5. Mixed masonry; 6. long stone; 7. Clay connecting brick. Bricks, stones and masonry are used to build city walls. When the slope of the terrain is small, bricklaying or masonry is parallel to the terrain, and when the local potential slope is large, the wall is built by horizontal descent method. A large number of beacon towers (beacon towers) are set up as information transmission systems in the beacon tower Great Wall system. In ancient times, the high platform used to light fireworks and transmit important news was an important military defense facility in ancient times, and it was the oldest but effective local telegraph.

This beacon tower was built to prevent the enemy from invading. In case of enemy situation, the beacon tower smokes during the day and ignites at night, and the beacon tower is connected with the platform to transmit messages.

According to historical documents, unearthed Han bamboo slips and field visits, there are a large number of beacon towers here, which extend far away from the Great Wall. According to the location and function of beacon towers, it can be divided into four groups: beacon towers located in the depths of the desert are the forefront of warning, and beacon towers set along both sides of the Great Wall transmit information along the route. A series of beacon towers from the Great Wall to the capital contacted the central government of the dynasty, and a number of beacon towers contacted local governments and garrison troops near the location of the Great Wall. According to the system of the Ming Dynasty, give a cigarette and fire a gun, which means that the enemy is about 100 people. Put two smoke bombs and two cannons to attack about 500 people; /kloc-more than 0/000 people held three cigarettes and fired three shots. Along the 50-kilometer Great Wall, * * * found more than 80 beacon towers, with an average distance of about 3 kilometers and the farthest distance of no more than 5 kilometers. "bonfire", two signals of ancient frontier warning, is called "bonfire" when smoking during the day and "flint" when making a fire at night. Beacon towers were built earlier than the Great Wall, but since the appearance of the Great Wall, beacon towers along the Great Wall have been closely integrated with the Great Wall and become an important part of the Great Wall defense system, and some of them were even built on the Great Wall, especially in the Han Dynasty. The imperial court attached great importance to the construction of beacon towers. Beacon, also known as bonfire, is a measure of ancient military intelligence warning, that is, when the enemy invades during the day, it burns smoke (bonfire), and when it invades at night, it ignites (bonfire) to alert all parties and superiors with visible smoke and lights. In Han Dynasty, beacon towers were called beacon towers and pavilions. In Tang and Song Dynasties, the word "beacon tower" was also extended to beacon towers. In the Ming dynasty, it was generally called a smoke pier or pier (the pier in the northwest of the Ming dynasty has the function of preventing the enemy, and the small one only has the function of watching, not lighting a bonfire). Beacon towers are generally about 10 Li apart, and in the Ming Dynasty, the distance was about 5 Li. When soldiers guarding Taiwan discovered the enemy's attack, they immediately lit a bonfire on the stage, and neighboring Taiwan followed suit after seeing it, so as to quickly convey the enemy's situation to the military central department. Geological form "Because of the terrain, the plug is made of danger." It is an important experience in building the Great Wall, which was affirmed by Qin Shihuang and later written by Sima Qian.

In historical records, the Great Wall was built in accordance with this principle in every subsequent dynasty. All the passes in Guancheng are built between two high mountains and canyons, or at the bend of a river, or where they will pass through the plain, which can not only control the danger, but also save manpower and material resources, and achieve the effect of "one person guards it, and ten thousand people can't force it". Building castles or beacon towers in dangerous places is also an option. As for building city walls, we should make full use of the terrain. For example, Juyongguan, Badaling and other Great Walls are all built along the back of the mountain. Some sections are steep from the outside of the city wall, but very gentle inside, which has the effect of "easy to defend but difficult to attack". In Liaoning Province, the Great Wall in Liaodong Town in the Ming Dynasty had a kind of dangerous mountain wall and split mountain wall, which used steep cliffs to split the cliff slightly and became the Great Wall. Some places completely use cliffs, rivers and lakes as natural barriers, which can be said to be wonderful. As a great project, the Great Wall has become a precious heritage of the Chinese nation. On June 25th, 20001year, the Great Wall, as an ancient building from the Spring and Autumn Period to the Ming Dynasty, was listed in the fifth batch of national key cultural relics protection units with the approval of the State Council, and it was a national 5A-level building. The main passes are Great Wall Pass, Jiayuguan Pass, Shanhaiguan Pass, Juyongguan Pass, Yumenguan Pass, Jingxingguan Pass, Niangziguan Pass, Yanmenguan Pass, Piantouguan Pass, Pingxing Pass, Gubeikou Pass, xifengkou Pass, Yulin Pass, Huangyaguan Pass, Waqiao Pass, Hushan Great Wall Pass, Raven Pass, Niuzhuang City, fenshuiguan, Ningyuan City and Yang Yang. Jinshanling, Dushikou, Zhangjiakou, Mashikou, Yangfangbaoguan, Shuikouguan, Zijingguan, Xuanhua City, Santunying, Sandaoguan, Damaoshankou, Yiyuankou, Jielingkou, Chongyukou, Xuliukou, Lengkouguan, Baiyangyuguan, Qingshan Pass, tiemenguan, Panjiakou, Longjingguan, Hongshankou and Shangguan. Baimaguan, Lupiguan, Hefangkou, Lianhuachiguan, Huanghua Chengguan, Qiaodaokou, Jiukonglou, Sihai Yekou, Juyansai Old Town, Gill Sai, Gaoque Sai, Datong City, Shahukou, Weilubaokou, Jinsuokou, Huangzeguan, Huangloukou, Ning Wuguan, Limin Baokou, Deshengkou and Zhenhongkou. There are two existing sites: Zhenqiang Fort, Qiangqiang Fort, Qiangmen Fort, Zhumabaokou, Bulubao Fort, Baoan Fort, Ninglubaokou, Broken Tiger Fort, Canhu Fort, Mabaokou, Yunshibao Fort, Shaojiabaokou, Dahebaokou, Defeated Tiger Fort, Yingen Fort, Jiangjunshe Fort, Yajiao Mountain and Eagle Fort. 1984, under the initiative of Comrade Deng Xiaoping, "Love my China and build my Great Wall", the ancient Xiongguan was completely renewed. 19 towers were successively restored, with a total length of 374 1 m, making the total sightseeing area reach19000m2. 1986, Badaling was rated as one of the sixteen scenic spots in new Beijing. From 65438 to 0987, the United Nations accepted the Great Wall of Wan Li as a "World Cultural Heritage". 1991August, Badaling, as the essence of the Great Wall of Wan Li, accepted the certificate of human cultural heritage issued by UNESCO at the Palace Museum in Beijing. 19911February, at the naming conference of the top 40 tourist attractions in China held in Zhuhai (there were 94 national candidate scenic spots, and 480,000 valid votes were collected), Badaling became the top 40 tourist attractions in China because of its famous scenic spots, with an absolute majority of 370,000 votes. Located in Yanqing, Beijing, Badaling Great Wall is the most representative section of Juyongguan outpost in Ming Dynasty, with an altitude of10/5 meters. It has always been a battleground for military strategists, an important military pass in the Ming Dynasty and an important barrier to the capital Beijing. Climb the Great Wall here and enjoy the magnificent mountain scenery. So far, more than 300 celebrities, including Obama, Nixon and Margaret Thatcher, have visited here. Badaling Scenic Area is famous for its magnificent landscape, perfect facilities and profound cultural and historical connotations. Known as one of the nine blockades in the world, it is the essence of the Great Wall of Wan Li and unique among the Great Wall of Ming Dynasty.

Badaling Great Wall Museum is a comprehensive museum with the theme of Wan Li Great Wall, which comprehensively reflects the history, politics, military affairs, economy and culture of the Great Wall. China Great Wall Museum is located outside Badaling Pass and opened on 1994. The whole museum has 9 exhibition halls with an area of 3.

000 square meters. There are many themes on display, among which "The Great Wall of Past Dynasties" shows the basic context of the emergence and development of the Great Wall; Ming Great Wall and Building Military Equipment show the reason and process of building the Great Wall in Ming Dynasty, the setting and distribution of military towns, the architectural structure and layout of the Great Wall and the equipment of weapons defense facilities. Economic and Cultural Exchange reproduces the historical fact that all ethnic groups inside and outside the Great Wall have developed together, exchanged and merged with each other for a long time. The "national art treasure house" shows that the Great Wall of Wan Li is the crystallization of thousands of years of traditional culture and art in China. "Love my China, repair my Great Wall" reflects the country's concern and protection of the Great Wall.

Mutianyu Great Wall Mutianyu Great Wall [3] is located in Huairou District and is one of the six new scenic spots in Beijing/KLOC-0. Juyongguan Great Wall in the west and Gubeikou in the east. The open 2250-meter section of the Great Wall is characterized by cribs on both sides of the Great Wall, especially the juxtaposition of three enemy towers in the viewing platform, the famous Great Wall landscape arrow buckle,

The horns at the western end of Mutianyu Great Wall and the inverted eagle are the essence of Wan Li Great Wall. Mutianyu Great Wall is a mountainous area with a vegetation coverage rate of over 90%. Mutianyu Great Wall is equipped with domestic first-class cable cars, and projects such as China Dream Stone Town and Shibeide Slide have been developed, forming an organic combination of Great Wall culture, stone culture, sports, fitness and entertainment. Former British Prime Minister john major, former US President Bill Clinton and many other foreign leaders have visited Mutianyu. 1992 was rated as the best tourist destination in Beijing. In 2002, it was rated as 4A scenic spot [4]. Mutianyu Pass has been a military fortress guarding Beijing since ancient times because of its very important geographical position. This section connects Juyongguan, Changping County, Beijing in the west and Gubeikou, Miyun County, Beijing in the east. Built in the Ming Dynasty, it is the eastern section of huanghua town, the north gate of the capital. Since ancient times, it has been called the northern barrier to guard the capital and the imperial tomb. Known as the "dangerous mountain". Located in the northeast of Miyun County, Beijing, Simatai Great Wall has five characteristics: danger, density, strangeness, cleverness and completeness.

Gubeikou Town, 20 kilometers away from Beijing/KLOC-0. It starts from wangjinglou in the east and ends at Houchuankou in the west, with a total length of 5.4 kilometers and 35 watchtowers. The whole section of the Great Wall is exquisite in conception, unique in design, novel in structure and different in shape, and it can be called the essence of the Great Wall in Wan Li. Professor Luo, a famous expert on the Great Wall, praised that the Great Wall in China is the highest in the world, and the Great Wall in Simatai is the highest in China. Simatai Great Wall 1987 is listed in the World Heritage List and belongs to the national key cultural relics protection unit. It is the only ancient building site in China that retains the original appearance of the Ming Dynasty. Gubeikou Great Wall Gubeikou Great Wall is the most complete in the history of China Great Wall.

The whole Great Wall system. It consists of the Northern Qi Great Wall and the Ming Great Wall, including Wohu Mountain, Panlong Mountain, Jinshanling and Simatai. Gubeikou is the Great Wall fortress between Shanhaiguan and Juyongguan. It is the throat of Liaodong Plain and Inner Mongolia leading to the Central Plains. It has always been a battleground for military strategists, especially in Liao, Jin, Yuan, Ming and Qing Dynasties. The competition for Gubeikou has never stopped, so the role of the Great Wall is particularly important. Arrow buckle the Great Wall? Jiankou Great Wall

Jiankou Great Wall is located in Badaohe Township, northwest of Huairou County, a suburb of Beijing, about 30 kilometers away from Huairou County. The mountains are varied, and the Great Wall above the steep peaks and cliffs is even more majestic and steep. The arrow buckle Great Wall twists and turns in a W shape, because the whole part of the Great Wall.

Shaped like a bow and arrow, hence the name. The Jiankou Great Wall is one of the most famous dangerous sections of Wan Li Great Wall in Ming Dynasty. It is the section with the highest photogenic rate in various Great Wall albums in recent years, and it has always been a hot spot in Great Wall photography. The Jiankou Great Wall is the most steep and majestic section of the Great Wall in Beijing, with severe natural weathering and no artificial decoration. It stretches for more than 20 kilometers from Niu Jiao side, South Building, Gate of Hell, Arrow Buckle Beam, East-West Neck Building, East-West Oil Basket Top, General's First Officer, Ladder, Eagle Flying Upside Down, Jiuyan Building and Jingjie to wangjinglou, fully demonstrating the wonders, dangers and dangers of the Great Wall.