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.
Yi'an District, which belongs to Tongling City, Anhui Province, is located in the central and southern part of Anhui Province, on the south bank of the middle and lower reaches of the Yangtze River, close to the developed Yangtze River Delta, between longitude 117 °42 "- 118 °10" 6 "east longitude and latitude 30 °45 12"-31 °07 56 "north. Fanchang and Nanling to the east, Qingyang and Guichi to the south, and Zongyang and Wuwei to the northwest. It is only 152 kilometers away from the provincial capital Hefei. In 2017, Yi'an District has jurisdiction over 6 towns and 2 townships, with a total area of 845 square kilometers. In 2016, there were 290932 registered residents (255000 permanent residents). In 2016, the gross domestic product (GDP) of Yi'an District reached 13.593 billion yuan. Yi'an, who first appeared in the first year of Tang Wende (AD 888), is the development of Chinese bronze civilization.