With one of the biggest saltwater tanks in the world, the most impressive aquarium in Japan is a wonderland for the eyes. A pioneering coral-breeding experiment has tons of information about the fragile tropical ecosystem, while tanks hold dangerous sharks, freaky deep-water species, and thousands of other wondrous sea creatures. The star attraction is the 30-foot-deep tank, big enough to hold three majestic whale sharks, a dozen graceful manta rays, and schools of fish big and small from across the Pacific. Viewing the whale sharks from below is a breathtaking experience. Take the highway Bus 111 from Naha Terminal to Nago (¥1,940; 90 minutes), and change to Bus 65, 66, or 70 (¥790; 60 minutes). By rental car, take the expressway one hour to Nago and continue on Route 58 to 449 and then 114 (about another hour) to Ocean Expo Park. In addition to Churaumi Aquarium, Ocean Expo Park also houses a great Oceanic Culture Museum and the Traditional Okinawa Village Arboretum.