City Museum

If your kid has ever wanted to crawl through a 10-story cave, slide down a spiral slide the height of a building, or climb on a decommissioned airplane bolted to a rooftop, City Museum in downtown St. Louis is the place. This isn't a museum in the traditional sense — it's an open-play wonderland built almost entirely from salvaged architectural and industrial materials, and it's unlike anything else in the country.

The main building spans multiple floors of interconnected tunnels, slides, and climbing structures. Kids can squeeze through narrow mesh tubes suspended several stories in the air, zip down the famous 5-story slide, explore an enchanted cave system that winds through the basement and main floors, and navigate a multi-level ball pit. The rooftop (open spring through fall) features a Ferris wheel, a school bus teetering over the edge, and more climbing structures with breathtaking downtown views.

For parents: this place requires active supervision — not because it's unsafe, but because kids will scatter in 30 seconds and the layout is intentionally labyrinthine. Wear comfortable shoes and resign yourself to getting dirty. The good news is there are plenty of benches and rest areas, and the on-site restaurant means you don't have to leave to refuel.

Younger siblings (under 5) can still have a blast in the Wee Museum, a basement area designed for little ones with scaled-down climbing and sensory play. It's a nice spot to anchor the adults with toddlers while older kids roam.

City Museum is open Thursday–Sunday (closed Mon–Wed), so plan your week accordingly. Evening visits on Fridays and Saturdays can get lively with older crowds, so families with young kids often prefer the Thursday or Sunday daytime window. Budget 3–5 hours minimum — most families find it impossible to leave in under 3.