As an emblem of Chinese civilization, a cultural phenomenon of world caliber, and another UNESCO endorsed world cultural heritage site, the 6350km Great Wall was in China's feudal years a mammoth defense bulwark that serpentines its way across mountains and valleys in the northern part of the country. The Great Wall came under construction in the 7th century BC. But it was Qinshihuang, the founding emperor of the Qin, who brought it to completion. Repeated extensions were done in later dynasties until the Ming. The 600-year-old Badaling Fortification in Yanqing county in northwest Beijing is representative of Ming sections of the Great Wall. The Great Wall looks equally breathtaking at such sections as Jinshanling, Mutianyu and Simatai.