What does it take to rank among the best aquariums in the U.S.? There's no single measure. Some might stand out for their scale, like the 10 million-gallon Georgia Aquarium. Others are notable for their interactivity, like at the Florida Aquarium, where you can snorkel next to bonnethead sharks. Then there are places with animals you can't see almost anywhere else, like the albino alligators at Newport Aquarium in Kentucky. Here are 10 spots that manage separate themselves from the rest of the more than 130 aquariums in the U.S.

Georgia Aquarium | Atlanta, GA

At 10 million gallons, this aquarium was the largest in the world when it opened in 2005, and it remains the largest in the U.S. A big part of the draw is the included presentations, where trainers show off the fascinating behavior of dolphins and sea otters.

Don't miss: The whale sharks, since the Georgia Aquarium is the only institution outside of Asia to house these gentle giants. In fact, the entire aquarium was designed around their exhibit.

Shop admission to the Georgia Aquarium starting at $43.51.

Cabrillo Marine Aquarium | San Pedro, CA

This aquarium has been showing off Southern California's aquatic life since 1935, but its move to a larger Frank Gehry–designed building in 1981 really put it on the map. The educational programs are particularly outstanding, especially the "Science at the Seashore" events that take visitors to the nearby beach to observe animals in the wild.

Don't miss: The Aquatic Nursery, a working laboratory where you can see how scientists grow and care for marine animals for research and other purposes.

Shop membership to the Cabrillo Marine Aquarium starting at $40.50.

Aquarium of the Pacific | Long Beach, CA

Head here for an amazing overview of life from all over the Pacific, from a giant Pacific octopus native to the Bering Sea to clownfish from the tropical islands of Palau. Visit the Shark Lagoon to interact with harmless bamboo and epaulette sharks in the touch pools (but don't try to pet the other sharks!).

Don't miss: The Lorikeet Forest, a walk-through aviary that's home to about 140 of the colorful birds. Buy a little cup of nectar and the birds will land on your shoulder and have a snack.

Shop admission to the Aquarium of the Pacific starting at $29.95.

Tennessee Aquarium | Chattanooga, TN

The exhibits at the Tennessee Aquarium are divided into two themed journeys housed in two separate (and massive) buildings. The original building, dubbed River Journey, traces the path of a raindrop from the Appalachian Mountains to the Gulf of Mexico—passing river otters, snapping turtles, and alligators along the way—while the Ocean Journey expansion building shows off species native to the open water.

Don't miss: The Butterfly Garden, where hundreds of free-flying butterflies from around the world float past exotic flowers and an indoor waterfall.

Adventure Aquarium | Camden, NJ

Every week is Shark Week at Adventure Aquarium, where you'll find a famous 40-foot shark tunnel that's home to more than 20 sharks, including sandbar, sand tiger, and blacktip sharks. Other creatures get their due at exhibits such as Hippo Haven, Sea Turtle Cove, and Piranha Falls.

Don't miss: Shark Bridge, an 81-foot-long, V-shaped rope bridge suspended just inches above the shark exhibit.

Shop admission to Adventure Aquarium starting at $19.99.

Monterey Bay Aquarium | Monterey, CA

Monterey Bay Aquarium has a reputation for inventiveness thanks to innovations like the staggering three-story-tall Kelp Forest, the first successful recreation of a living kelp forest indoors and still one of the tallest aquarium exhibits in the world. Elsewhere you'll find touch pools, a sea otter habitat, and an "Open Sea" tank with a 90-foot window onto hammerhead sharks, sea turtles, and more.

Don't miss: The daily feedings, which take place at set times and are included with admission. Watch everything from penguins to sea otters to sharks take their lunch break while presenters narrate and provide background info.

The Florida Aquarium | Tampa, FL

The 500,000-gallon, floor-to-ceiling coral reef exhibit is impressive enough, but the real standout here is the program of immersive experiences. Anyone over age 6 can participate in snorkeling sessions alongside fishes, sea turtles, and bonnethead sharks, while certified divers can venture into the aquarium's largest habitat for encounters with moray eels and sand tiger sharks.

Don't miss: The pythons, alligators, and river otters who populate the glass atrium of the simulated Florida Wetlands Trail.

Shop admission to the Florida Aquarium starting at $24.65.

SEA LIFE Grapevine Aquarium | Grapevine, TX

Strolling through the 360-degree Ocean Tunnel at this Dallas–Fort Worth area aquarium is as close as you can get to walking along the ocean floor without a whole lot of fancy equipment. The aquarium is also heavy on interactive exhibits, including a rockpool where you can touch live sea stars, urchins, and anemones.

Don't miss: The daily talks and presentations, which let guests watch stingrays feed and see animals from the rainforest exhibit up close.

Shop admission to SEA LIFE Grapevine Aquarium starting at $17.

National Aquarium | Baltimore, MD

Size is on the National Aquarium's side: it hosts more than 20,000 specimens in 2.2 million gallons of water across 3 separate pavilions. The most recent addition is Australia: Wild Extremes, where birds, snakes, lizards, and crocodiles from Down Under live inside a glass pavilion similar to a walk-in aviary.

Don't miss: Dolphin Discovery, home to a colony of 7 bottlenose dolphins (6 of which were born in the aquarium).

Newport Aquarium | Newport, KY

You may not think "sea life" when you think "Kentucky," but maybe you should. With 70 exhibits across 14 galleries, this million-gallon aquarium has plenty to see, from a color-changing Giant Pacific Octopus to two extremely rare white American Alligators (named Snowball and Snowflake, naturally).

Don't miss: The shark rays, three extraordinarily rare animals that resemble a cross between, well, sharks and rays—but with striking eyes that look almost human.