The Saint Louis Science Center is one of only two science centers in the country with no general admission charge. The Science Center consists of three buildings. The main Science Center Building and the Exploradome exhibition hall are located just south of Forest Park on 5050 Oakland Avenue. These facilities are connected to the James S. McDonnell Planetarium located within Forest Park via a walkway across I-64.

The Saint Louis Science Center has its roots when the Academy of Science of St. Louis was founded in 1856. The Academy's members displayed personal collections and published scientific papers for the next 130 years. In 1959 the Museum of Science and Natural History opened in St. Louis' Oak Knoll Park. In 1963 the McDonnell Planetarium in Forest Park opened. The two merged in 1985 to become the St. Louis Science Center in Forest Park. By 1989 more than a million visitors came to the Science Center overwhelming the facility's exhibit space and a capital campaign was initiated to build a new facility and renovate the Forest Park Building. The new building opened in 1991 and during its first two months it became the most-visited science center in the world. The next year the Forest Park Building reopened and continued its tradition of focusing on space-related topics. The Exploradome, an inflatable structure, gives the Science Center, more room for large traveling exhibitions, opened in 1997.

The main building holds many interesting attractions. The "DNA Zone" is the only gallery in the world completely dedicated to the emerging science of biotechnology and genetics. "Cyberville" is an exhibit that focuses on computers, virtual reality and the Internet. "Structures" explains how bridges and large buildings are constructed. The "Human Adventure" exhibit explores senses, creativity, and culture. There are three "Ecology and the Environment" exhibits - Past, Present, and Future. The Discovery Room is a hands-on science experience for families with young children.

The McDonnell Planetarium houses the International Boeing Space Station that allows visitors an opportunity to learn what it is like to live in space through interactive exhibits, laboratories, and live demonstrations. In the SkyBay, over 9,000 twinkling stars and glowing planets can be seen slowly moving across the new 80 sq. ft. dome. The OMNIMAX® theatre is a four-story dome theatre with wrap-around sight and sound. The Saint Louis Science Center is handicapped accessible. Assistive Listening Devices, Braille visitor guides, TDD machines and wheelchairs are available for check out.