Osaka Aquarium Kaiyukan opened in 1990 in Minato Ward as the largest public aquarium in the world at the time, and remains one of the biggest today. Located on Osaka Bay next to the Tempozan Ferris Wheel, it holds over 10,900 tons of water across 27 tanks and 16 exhibits themed on the Pacific Ring of Fire. The centerpiece 5,400 cubic meter Pacific Ocean tank houses whale sharks and manta rays. Visitors follow a single spiral route down from the 8th floor.
Address: 1 Chome-1-10 Kaigandori, Minato Ward, Osaka 552-0022, Japan, a short walk from Osakako Station. Kaiyukan traces marine habitats around the Pacific Rim, from Arctic tundra to Japanese forest streams to the tropics, spread over 8 floors that visitors descend via escalator and spiral ramp. Its main tank holds whale sharks, giant manta rays and hammerhead sharks; the aquarium is also a research center for elasmobranchs and achieved the first captive conception of a giant devil ray in 2022. It is Japan's most-visited aquarium (as of 2017) and passed 85 million total visitors in 2024. Google reviews rate it 4.5/5 from over 60,000 visitors.