River's Edge

River's Edge is one of the standout sections of the St. Louis Zoo, and the best part is that the entire zoo is free. No tickets needed, no reservations — just show up. The only cost is parking ($15 in the zoo lot) or you can take MetroLink and skip that entirely.

This section of the zoo focuses on animals from the world's great river systems. The stars are the hippos, elephants, and cheetahs. The hippo exhibit has a massive underwater viewing window where you can watch these 3,000-pound animals glide through the water like they're weightless.

Little kids are absolutely mesmerized by it. The elephant habitat was renovated in recent years and it's one of the most spacious, well-designed elephant areas in any American zoo.

River's Edge sits at the back end of the zoo, so it takes about 15-20 minutes to walk there from the main entrance. Pro tip: start your visit here and work your way back toward the entrance. Most visitors do the opposite, which means River's Edge is emptiest in the morning and gets crowded by early afternoon.

The paths are fully paved and stroller-friendly. There's decent shade coverage from trees along the route, but you'll still want sunscreen and hats in summer.

For a family of 4, you can genuinely do this for free if you bring your own food and take public transit. Even with parking and buying lunch, you're looking at maybe $40-60 total. You won't find a better zoo experience at that price point anywhere in the country.

The zoo is open 9am-5pm daily, with extended summer hours. The animals are most active in the morning, so aim to be at River's Edge by 9:30am for the best experience.