Six Flags America 13710 Central Ave, Upper Marlboro, MD20774 Six Flags has been entertaining families since 1974. Enjoy such attractions as the Superman Ride of Steel, the Joker,…More the Batwing and Hurricane Harbor Park. For young children, there is Thomas Town, which is based on the famous children’s book, plus Loony Tunes Movie Town. Group discounts are available, as well as picnic areas for company, school or church outings. On September and October weekends, the park is turned into the annual Fright Fest, which features haunted houses and Halloween decorations.