St. Louis Aquarium at Union Station

The St. Louis Aquarium at Union Station sits inside the beautifully restored historic train terminal in Midtown, combining a classic aquarium experience with one of St. Louis's most architecturally striking indoor spaces. For families with kids ages 2–12, it's a reliable, weather-proof outing that delivers real wow moments alongside genuine educational value.

The layout moves you through a series of themed zones — freshwater habitats, tropical ocean tanks, jellyfish galleries, and the centerpiece shark tunnel, which is a long walk-through acrylic tube surrounded on all sides by sharks, rays, and large open-water fish. Kids tend to stop dead in the tunnel and look up for several minutes, which is exactly what you want. The tunnel is the single best moment in the aquarium and worth lingering in.

Interactive elements are well placed throughout: the ray touch pool near the entrance is a gentle first experience for kids who are tentative about touching, and the variety of tank sizes — from huge panoramic tanks down to small, eye-level tanks where kids press their face to the glass — keeps the pacing varied and engaging.

Strollers are fully welcome and the aquarium's wide paths make navigation easy even with a double stroller. Nursing and changing rooms are available. Because it's entirely indoors and climate-controlled, it works in any weather and on any season — a key logistical plus for St. Louis families dealing with summer heat or winter cold.

Buy tickets online ahead of time; the discount is meaningful and the ticket line on busy days can add 20–30 minutes. Kids under 3 are typically free. Combining the aquarium with the other Union Station attractions — the Ferris wheel, mini golf, and entertainment options — makes for a genuinely full family day without ever moving your car.