Eureka, MO
Eureka is a city mainly in St. Louis County, with a small portion in Jefferson County, Missouri, adjacent to Wildwood and Pacific. It is in the extreme southwest of the Greater St. Louis metro area. As of the 2020 census, the city had a population of 11,646. Since 1971, Eureka has been known as the home of the amusement park Six Flags St. Louis. Source: Wikipedia