The hook
A ten-storey former shoe factory that a sculptor spent years turning into a climbable structure — caves of rebar and concrete, a ten-storey slide, two decommissioned planes bolted to the outside, and a ferris wheel on the roof. There is nothing else like it anywhere, and it is not really a museum.
01Why it's worth it
Bob Cassilly was a classically trained sculptor, and City Museum is his enormous unfinished artwork. He and his crew filled an abandoned shoe warehouse with the things a city throws away — old chimneys and cornices, salvaged ironwork, limestone, construction cranes, a pair of aircraft fuselages — and welded them into something you get inside of rather than look at.
The experience is unusual because almost nothing is explained or fenced. You climb into a tunnel and it goes somewhere. Wire-mesh tubes run between buildings ten storeys up, outside, over the street. There is a school bus cantilevered off the roof edge. There are caves under the ground floor with no map. Adults spend the first twenty minutes deciding whether they are allowed to do this, then spend four hours doing it.
It is worth knowing that this is a real building made of real salvaged material, not a themed attraction. The surfaces are concrete and steel; the edges are hard. People do bruise and scrape themselves. That is the trade for a place that treats you like an adult who can judge a gap.
The salvage is also the story. Much of what you are climbing on came out of buildings St. Louis demolished — a city that has lost an enormous amount of its own architecture. Cassilly's answer to that was to drag the pieces indoors and let children climb on them. He died in 2011, on site, working on another project; the museum has kept building.
02How to experience it
Go on a weekday if you can. Wear clothes you do not care about and shoes you can climb in — no sandals. Leave bags in a locker, because you will want your hands. Do the caves and the ten-storey slide early before the queue builds, and save the rooftop for last. Friday and Saturday evenings it runs late as an adults-heavy scene, which is a genuinely different and quite good version of the place.
From the locals
The strongest endorsement in the whole corpus comes from a thread asking for the best museum anyone had been to in their life — a field containing the V&A, the Field Museum and the Rijksmuseum. One answer: "for the 'other' category it's the City Museum in St. Louis. It's worth taking a trip to St. Louis for."
That framing recurs. From a 2025 thread on the most unlikely city anyone had taken a holiday in: "St Louis City Museum is one of the coolest places I have ever been." From a road-tripper weighing it against the monument down the road: "the Gateway Arch is the obvious attraction here, but the City Museum in STL is probably the most fun you can have in the Midwest. It's basically an all-ages playground in a 10-storey building where all of the attractions are made out of repurposed materials. Think Willy Wonka."
The rest of the enthusiasm is people struggling to name the category. "Absolutely insane and worth seeing with kids or without." "The loosest definition of the term 'Museum' possible — it's more a massive playground for adults." And, from someone in an urban-exploration thread recognising a photographed industrial ramp: "there is a place with a 10-storey slide that looks just like this. St Louis City Museum. It's basically McDonald's play place for grownups."
The one piece of practical advice, which is worth following exactly: "grab a pair of tennis shoes and jeans with sturdy knees."