The City Museum is situated in a 10-story former shoe factory in St. Louis. The 600,000 square-foot urban playground, conceived by artist and sculptor Bob Cassilly, opened in 1997.
The jungle gym (above) has two repurposed airplanes, two 10-story slides, a rooftop Ferris wheel and a cantilevered school bus that juts out from the roof. The museum also has subterranean caves, a pipe organ, hundreds of feet of tunnels that traverse from floor to floor, an aquarium, ball pits, a shoe lace factory, a circus arts facility, restaurants, and even a bar. It looks like a total blast.
As if that weren't enough all the materials used to build the museum including salvaged bridges, old chimneys, construction cranes, and miles of tile are sourced locally, making the entire endeavor a massive recycling project.
Although Cassilly passed away in 2011, the museum is perpetually under construction as new features are added or improved
More amazing photographs: Colossal