This aquarium challenges you to really imagine life under and around the sea. Seals bark outside the West Wing, its glass-and-steel exterior constructed to mimic fish scales. This facility has a café, a gift shop, and changing exhibits; one exhibit, "Amazing Jellies," features thousands of jellyfish, many of which were grown in the museum's labs. Inside the main facility, you can see penguins, sea otters, sharks, and other exotic sea creatures -- more than 2,000 species in all. Some make their home in the aquarium's four-story, 200,000-gallon ocean-reef tank, one of the largest of its kind in the world. Ramps winding around the tank lead to the top level and allow you to view the inhabitants from many vantage points. Don't miss the five-times-a-day feedings; each lasts nearly an hour and takes divers 24 feet into the tank. From outside the glassed-off Aquarium Medical Center, you can watch veterinarians treat sick animals -- here's where you can see an eel in a "hospital bed." At the "Edge of the Sea" exhibit children can gingerly pick up starfish and other creatures, while "The Curious George Discovery Corner" is a fun spot for younger kids. Whale-watch cruises leave from the aquarium's dock from April to October, and cost $36.70. Across the plaza is the aquarium's Education Center; it, too, has changing exhibits. The 6 1/2-story-high IMAX theater takes you on virtual journeys from the bottom of the sea to the depths of outer space with its 3-D films. The gift shop seems to have every stuffed aquatic animal ever made.