It is traversed by the Yin Mountains, which divide it into the upper and lower areas. Covering a total area of 36,800 square kilometers, it is home to a population of 4.07 million people.Throughout Chinese history, Zhangjiakou has always been a strategically important location, with the Great Wall winding through its land. Since the Ming and Qing dynasties, the Zhangku Road, connecting Zhangjiakou with Ulan Bator, formerly known as Kulun, and extending to Chita in Russia, has served as an important channel for trade and cultural exchanges. It is regarded as a section of the grassland Silk Road. Click the video and explore the colorfulness and endless charm of the Olympic city.