Eureka is a city located in St. Louis County, Missouri, United States, between St. Louis and Pacific, Missouri, along Interstate 44.The city is 2 miles (3 km) west of the former site of Times Beach, the site of dioxin contamination discovered the area was cleaned up and became Route 66 State Park. Eureka is known for its antique shopping. Once a year a candlelight walk is held in old town Eureka. Visitors use this night to tour the numerous antique shops within walking distance of one another. Also within walking distance within "Old Town" Eureka are many restaurants popular with local residents. Eureka is the home to the last amusement park to be built under the "Six Flags Over" name.