Great Wall of China / Wanli Changcheng (begun by Emperor Qin Shi Huangdi 220-210 BC; what exists today is of the Ming Dynasty; 15th century; about 2;500 km long; since 1987 UNESCO World Heritage Site);Mutianyu (section of the Great Wall of China in Huairou District; 70 km northeast of Beijing; started in the middle of the 6th century during the Northern Qi Dynasty; today's construction started in 1376 under General Xu Da during the Ming Dynasty and completed in 1569).- View of the Great Wall in Mutianyu section in autumn. -Photo; undated.