The Great Wall, also known as the Great Wall, is a military defense project in ancient China. It is a tall, solid and continuous terrace to limit the actions of enemy horsemen.
The Great Wall is not a simple isolated city wall, but a defense system which takes the city wall as the main body and combines with a large number of cities, barriers, pavilions and signs.
The history of the Great Wall can be traced back to the Western Zhou Dynasty, from which came the famous allusion "the princes of beacon fire opera" which took place in the capital of Chengjing (now Xi'an, Shaanxi Province).
During the Spring and Autumn Period and the Warring States Period, countries fought for hegemony and defended each other. The construction of the Great Wall reached its first climax, but at this time the length of the construction was relatively short.
After the Qin Dynasty destroyed the six countries and unified the world, Qin Shihuang joined and repaired the Great Wall of the Warring States, which was known as the Great Wall.
The Ming Dynasty was the last dynasty to build the Great Wall. Today most of the Great Wall people see is built at this time.
长城，又称万里长城，是中国古代的军事防御工程，是一道高大、坚固而连绵不断的长垣，用以限隔敌骑的行动。长城不是一道单纯孤立的城墙，而是以城墙为主体，同大量的城、障、亭、标相结合的防御体系。
长城修筑的历史可上溯到西周时期，发生在首都镐京（今陕西西安）的著名的典故“烽火戏诸侯”就源于此。春秋战国时期列国争霸，互相防守，长城修筑进入第一个高潮，但此时修筑的长度都比较短。
秦灭六国统一天下后，秦始皇连接和修缮战国长城，始有万里长城之称。明朝是最后一个大修长城的朝代，今天人们所看到的长城多是此时修筑。
扩展资料：
一、长度
由于年代久远，早期各个朝代的长城大多数都残缺不全，保存得比较完整的是明代修建的长城，所以人们一般说的长城指的是明长城，所称长城的长度，也就是明长城的长度。
国家文物局和国家测绘局2009年4月18日联合公布，明长城东起辽宁虎山，西至甘肃嘉峪关，从东向西行经辽宁、河北、天津、北京、山西、内蒙古、陕西、宁夏、甘肃、青海十个省（自治区、直辖市）的156个县域，总长度为8851.8千米。经过壕堑359.7千米，自然天险2232.5千米。
2012年6月5日，国家文物局在北京居庸关长城宣布，历经近5年的调查认定，中国历代长城总长度为21196.18千米，包括长城墙体、壕堑、单体建筑、关堡和相关设施等长城遗产43721处。
这是中国首次科学、系统地测量历代长城的总长度。此次长城的调查和认定，不仅认定了2009年测定的明长城长度，还开展了秦汉及其他时代长城的资源调查。
二、边带发展
自秦汉至明清，长城沿线的许多关口成为农、牧两大经济、文化系统民族交易的场所或中心，有的逐渐发展成为长城沿线的重要城镇。长城既保证了农业经济、文化与畜牧业经济、文化的正常发展，又为二者的交流和相互补充提供了场所和方便。
又起着调解两种经济，使农、牧业经济朝着主辅相互配合的方向发展的重要作用。因此，长城不单纯是曾起过将两种经济、文化分割开来的作用，还曾担负着将两种经济、文化紧紧系在一起的重任。
秦汉之时，累计投入的兵民有近千万之众。秦始皇在修筑长城的同时，即着手加强边境地区的开发建设，揭开了屯田戍边、开发边区的序幕。汉代由于修筑长城的时间较长，曾有多人提出移民实边的建议，这些建议先后被汉政府采纳接受并组织实施。
移民和戍守长城的军人一起，开垦荒地进行农耕，不但加速了边区的经济开发，节省了政府的大量军费开支，而且大大减少了长途运输之苦，并将华夏文化远播四方。
参考资料来源：百度百科-长城
The Great Wall is a treasure of Chinese civilization, is one of the world's cultural heritage, but also with the Egyptian pyramids building, or human miracle. In the far more than 2000 years ago, is the working people with flesh and blood built the great wall. The Great Wall is the ancient Chinese people's wisdom, but also the symbol of the Chinese nation. Spring and autumn and the Warring States period, in order to prevent the invasion of feudatory states in other countries, the construction of Beacon Tower, and the walls connects, formed the earliest the Great Wall. Later kings almost reinforcement build the Great Wall. It was up to several million, so it is also called" the great wall". According to the record, Qin Shihuang used the nearly million labor to build the Great Wall, total 1/20 of the population. There were no machinery, all labor and all completed by manpower, work environment and high mountains and lofty hills, cliff, very difficult. The Great Wall east to Shanhaiguan, West to Gansu and east to Jiayuguan, the Yalu River. From east to west through 10 provinces and municipalities. The Great Wall for a total length of 88518000 meters, in which the artificial wall length of 6254239.662 meters, the natural formation of the trench and a length of 25942342.265 meters. The Great Wall was built in the spring and autumn and the Warring States period, which lasted for more than 2000 years, total length amounts to 5320000 meters of above. Today we are referring to the great wall of Ming dynasty built the Great Wall, it is west of Gansu province in Western China Jiayuguan in Northeast China's Liaoning Province, east to the Yalu River, 6350000 meters long. It is like a powerful dragon, the mountains, the cliffs, wear a prairie, the desert, ups and downs in the top of the high mountains and lofty hills, the other side of the Yellow River and the coast of Bohai. At all times and in all countries, where people went to the Great Wall are all amazed its Pangbo momentum, the grand scale and arduous engineering. The Great Wall is a rare treasure, but also extraordinary art heritage, which is the symbol of the Chinese nation be secure against assault ever in the world 's great strength and will, is the pride of the Chinese nation, but also the entire human pride.本回答被网友采纳