Zhangjiakou - Prefecture-level city in Hebei, People's Republic of China

"Zhangjiakou also known as Kalgan and several other names, is a prefecture-level city in northwestern Hebei province in Northern China, bordering Beijing to the southeast, Inner Mongolia to the north and west, and Shanxi to the southwest. By 2019, its population was 4,650,000 inhabitants on 36,861.56 square kilometres (14,232.33 sq mi), divided into 17 Counties and Districts. The built-up area made of Qiaoxi, Qiaodong, Chongli, Xuanhua, Xiahuayuan Districts largely being conurbated had 1,500,000 inhabitants in 2019 on 1,412.7 km2 (545.4 sq mi). - Wikipedia"