From the outside, the Great Wall is just an ancient building, or an ancient military defense system. But it contains many contents, such as military affairs, politics, history, culture, geography, architecture, nationality, economy and so on. Everyone has a different understanding of the Great Wall, and this understanding comes from his understanding and mastery of the connotation of the Great Wall. Everyone in China knows the story of Qin Shihuang repairing the Great Wall. In fact, someone had been repairing the Great Wall before Qin Shihuang, but the scale of repairing the Great Wall was not as large as that in the later period of Qin Shihuang, so it was little known.
A scholar who studies the Great Wall summed up the Great Wall in two sentences: it lasted for more than 2,000 years, with a span of more than 10 Wan Li, which means that it took more than 2,000 years for the Great Wall to be built from the beginning to the end, and the total length of all the Great Walls built in these two thousand years exceeded 10 Wan Li. For more than two thousand years, at the foot of the Great Wall, a magnificent historical drama has been staged. In the meantime, there is a life-and-death war of the nation, and there is also peace in which brothers live in harmony. However, whether it is war or peace, the Great Wall has always been a link, linking people living on both sides of it. There is an old saying in China that unity is strength, or unity is strength. Today, when we look back at the Great Wall, can we also say: The Great Wall, the city of the Chinese nation!