Great Wall of China
The Great Wall of China is not long, but is a collection of short walls that follow the shape of the mountains of northern China. On April 18, 2009, after an accurate investigation by the government of the People's Republic of China, it was announced that the giant wall constructed during the Ming Dynasty period was 8,851 km.
According to historical records, after a long wall was built by Ming, the term "changcheng" was known. Previously the term was not found. The term "Great Wall of China" in Chinese is "wanli changcheng", meaning "wall that is 10 thousand li long". Today the term is officially used.
In 2009, the Survey and Mapping Agency and the Cultural Heritage Administration of the People's Republic of China conducted research to recalculate the length of the Great Wall of China. The results show that the Great Wall of China is longer than the range currently known. According to measurements, the overall length of the wall reaches 8,850 km. The project has also found parts of other walls that are 359 km long, ditches along 2232 km, and natural barriers such as hills and rivers along 2232 km. The average range of the Great Wall of China is 5000 km, generally quoted from various historical records.
The Great Wall of China is said to be one of the man-made buildings seen from space with the naked eye. However, after an investigation by astronauts, this perception was incorrect. From low orbit, man-made buildings such as roads, ships, cities and others can indeed be seen, but when passing through the orbit of the earth with tens of thousands of feet high, none of the objects on the surface of the earth can be seen, including The Great Wall of China. This was confirmed by NASA statement: "The Great wall can only be seen from the Shuttle, so it won't be possible to see it from the moon with the naked eye".