Ancient China Great Wall of China one of the great works. Built in the Warring States (770 ~ 476 BC),
Today the survivors built for the Ming Dynasty. West from Jiayuguan in Gansu, Liaoning Dandong Yalu River east to Tiger Pass, runs through Gansu, Ningxia, Shaanxi, Shanxi, Mongolia, Hebei, Liaoning and other places. Strategically located along the gateway or hub are provided, such as Shanhaiguan, Juyongguan, Niangziguan so. Referred to as the Great Wall. The initial construction of the Great Wall is the Warring States Period of Yan, Zhao and other countries, aims to defend against the invasion of northern mixed.
Emperor Qin Great Wall was to connect them off. It was reported that the soldiers spent three hundred thousand and millions of people and slaves. However, the Great Wall and not to completely prevent the effect of alien invasion. Because the Great Wall is completed, the North still often mixed across the Great Wall of China border attack on a village, snatch crops or livestock.
The Great Wall is the only ever seen in space, three-dimensional structures can be. Modern technology to build is not easy, but our country can escape from building in the Spring and Autumn Period 2,000 years ago, is rare. Department of the Great Wall of building materials using local resources, rather different parts. Han Dynasty Great Wall built with mud and reeds. Wall sizes vary to Juyongguan area, the height of about 8.5 meters wide and 8.5 meters lower, the upper width of 5 meters. Every 70 to 100 meters with a Fort (equivalent to the tower), about 12.3 meters high, the majority of the fortress, is a heavy, vital to the home of two triple.
East through the mountains or hilly Great Wall, called as "Cut Hill mound," and "insurance system with force", undulating winding, majestic form; the middle of the dry western part of the region are sparsely populated, only the color desolate. If the boarding during the Yanmenguan, Juyongguan, Gubeikou or Shanhaiguan, facing the situation of China's great rivers, the stunning ancestors exploiting the boundary of the difficult, but unlimited ambitions are aroused.
意思：中国万里长城 我国古代伟大的工程之一.始建于春秋战国（公元前770～476）,
今存者为明代所修建.西起甘肃嘉峪关,东到辽宁丹东鸭绿江畔的虎山口,横亘甘肃、宁夏、陕西、山西、蒙古、河北、辽宁等地.沿线险要或交通要冲都设有关口,如山海关、居庸关、娘子关等.简称为长城.最初修筑长城的是战国时代的燕、赵等国,目的是为了防御北方异族的侵袭.
秦始皇后来将这些断断续续的长城连接起来.据说当时动用了三十万的兵士和数百万的人民与奴隶.不过,长城并不能达到完全防止异族入侵的效果.因为长城完成之后,北方异族依然常跨越长城,偷袭中国边境的村落,抢夺农作物或家畜.
长城是有史以来唯一在太空中可见到的三度空间建筑物.以现代科技来修筑都不容易,而我国竟能建筑于两千多年前的春秋战国时代,实在难得.长城的建材系就地取材,各地颇不相同.汉代以泥和芦苇修筑长城.长城体积也各不相同,以居庸关一带来说,高约8.5公尺,下部宽8.5公尺,上部宽约5公尺.每隔70～100公尺有一堡寨（相当于城楼）,高约12.3公尺,多数堡寨是一重的,要害之地则置两、三重.
长城东段经过山地或丘陵地,古称「堑山堙古」、「用险制塞」,起伏蜿蜒,形式雄伟；中段、西段都在干燥区域,人烟稀少,仅色荒凉.如果登临其间的雁门关、居庸关、古北口或山海关,遥望我国山川的伟大形势,将令人叹服先民开疆拓土的艰难,而激起无限的壮志雄心.
