The Shedd is one of the world’s largest indoor aquariums and houses thousands of river, lake, and sea denizens in standard aquarium tanks and elaborate new habitats within its octagon-shaped marble building. Truly, the only problem with the Shedd is its relatively steep admission price. A CityPass can save you money if you visit enough of the other included attractions.

The first thing you’ll see as you enter is the Caribbean Coral Reef. This 90,000-gallon circular tank occupies the Beaux Arts–style central rotunda, entertaining spectators who press up against the glass to ogle divers feeding nurse sharks, barracudas, stingrays, and a hawksbill sea turtle. A roving camera connected to video monitors on the tank’s periphery gives visitors close-ups of the animals inside, but I’d recommend sticking around to catch one of the daily feedings, when a diver swims around the tank and (thanks to a microphone) talks about the species and their eating habits.

The exhibits surrounding the Caribbean coral reef recreate marine habitats around the world. The best is Amazon Rising: Seasons of the River, a rendering of the Amazon basin that showcases frogs and other South American species, as well as fish (the sharp-toothed piranhas are pretty cool).

The Abbott Oceanarium, with a wall of windows revealing the lake outside, replicates a Pacific Northwest coastal environment and creates the illusion of one uninterrupted expanse of sea. On a fixed performance schedule in a large pool flanked by an amphitheater, a crew of trainers puts dolphins through their paces of leaping dives, breaches, and tail walking (there’s an extra charge to see the show). If you’re visiting during a summer weekend, consider buying tickets in advance to make sure you can catch a show that day.

Wild Reef—Sharks at Shedd is a series of 26 connected habitats that house a Philippine coral reef patrolled by sharks and other predators. The floor-to-ceiling windows bring the toothy swimmers up close and personal (they even swim over your head at certain spots). And if you’re here with kids, you’ll want to stop by the Polar Play Zone, where little ones can pet a starfish, try on a penguin suit, or get a good look at the real thing—the Play Zone is home to a dozen rockhopper penguins. For a spectacular view of Lake Michigan, check out the kid-friendly Soundings Cafe. There’s also a food court.

Allow 2 to 3 hours.