在战国时代的文献就出现“长城”一词,专指齐、燕等国建的“边防工程”,到秦始皇统一六国后的长城已是中国历史上第一条的“万里长城”了。长城是我国古代劳动人民智慧和血汗的结晶,它和埃及的金字塔都是人类最宏大的建筑,而且历史悠久。但是,为什么只有金字塔入选“世界七大奇 The word “Great Wall” appeared in the Warring States period, specifically referring to the “Frontier Defense Project” of Qijian and Yan and other countries. After the emperor Qin unified the six countries, the Great Wall was the first “Great Wall” in Chinese history . The Great Wall is the crystallization of the wisdom and bloodshed of the working people in ancient China. It and the Egyptian pyramids are the most magnificent buildings of mankind and have a long history. However, why only the pyramid selected “seven wonders of the world.”