The Kansas City metropolitan area is a bi-state metropolitan area anchored by Kansas City, Missouri. Its 14 counties straddle the border between the U.S. states of Missouri (9 counties) and Kansas (5 counties). With 8,472 square miles (21,940 km2) and a population of more than 2.2 million people, it is the second-largest metropolitan area centered in Missouri (after Greater St. Louis) and is the largest metropolitan area in Kansas, though Wichita is the largest metropolitan area centered in Kansas. Alongside Kansas City, Missouri, these are the suburbs with populations above 100,000: Overland Park, Kansas; Kansas City, Kansas; Olathe, Kansas; Independence, Missouri; and Lee's Summit, Missouri.
Yanshan County belongs to Cangzhou City, Hebei Province, with a total area of 800 square kilometers, located in the southeast of Cangzhou City, facing the Bohai Sea to the east, Beijing and Tianjin to the north and Shandong to the south. It is the center of the "two provinces" (Hebei Province and Shandong Province) and "three cities" (Cangzhou, Dezhou and Binzhou). It is known as "Jilu Hub" and "Beijing-Tianjin Portal". It is 120 kilometers away from Tianjin, 220 kilometers from Beijing, 160 kilometers from Jinan, 50 kilometers away from Huanghua Port and 110 kilometers away from Tianjin Port. You can go to sea in half an hour and board the plane in one hour. Yanhuang Railway, New Beijing-Shanghai Expressway, 205 National Highway and other national trunk lines run through the county, and the three major railway lines of Beijing-Kowloon Railway, Beijing-Shanghai Railway (passenger dedicated line) and Shuohuang Railway pass by the major traffic arteries such as Shihuang Expressway and Tianjin-Shantou Expressway. The total area of the county is 800 square kilometers, with cultivated land.