Six Flags Great America (formerly known as Marriott's Great America) is a 273-acre (110 ha) theme park in Gurnee, Illinois, United States, between Chicago and Milwaukee. Owned and operated by Six Flags, the park features more than 45 attractions, including 16 roller coasters, and an adjacent water park named Hurricane Harbor Chicago. It frequently ranks as one of the top 20 most-visited amusement parks in North America, with an estimated 3.04 million visitors in 2024. In 1973, the Marriott Corporation, a hospitality company, announced plans to build a regional theme park located in the Chicago metropolitan area. Named Marriott's Great America, the park would be one of two near-identical Americana-themed parks built by the Marriott Corporation. The park opened to the public on May 29, 1976. It was later sold to the amusement park operator Six Flags in 1984, which renamed it Six Flags Great America. Since then, the park significantly expanded under Six Flags ownership, being positioned as a well-performing park within the company. The park is divided into 12 themed sections, including areas based on Americana and DC Comics, along with children's areas. Operating seasonally from April to November, the park hosts its annual Halloween event Fright Fest in the fall. Six Flags Great America has received recognition from organizations including the International Association of Amusement Parks and Attractions (IAAPA), American Coaster Enthusiasts (ACE), and Amusement Today. It has been featured in popular culture such as Richie Rich, Dinner: Impossible, and Run BTS.