Mutianyu Great Wall, the longest great wall section, stretches 5400m, with 2250m open to the public and densely dotted 23 watchtowers. The Zhengguan pass with 3 watchtowers standing side by side on the eastern part is rarely seen at other great walls. Other famous tourist sites like Flying eager, Jiankou (Arrow Nock) are on the west side of Mutianyu Great Wall. Being the ancient military defence project, Great Wall is symbol and proud of China. It is convenient to visit Great Wall from Beijing. There are many sections of Great Wall around Beijing city. Badaling Great Wall is the site of the most visited section of the Great Wall partly because it is close to Beijing city and connected with urban area by expressway.