Underwater Aquarium Sea Donut

The Sea Donut is one of only two floating aquariums in Japan-and the only one in western Japan. Located on Maejima Island in Kami-Amakusa, Kumamoto Prefecture, the aquarium’s distinctive donut-shaped structure floating on the sea makes for a striking sight.

Themed as a “Traveling Aquarium,” it features five exhibition zones that recreate the unique marine environments surrounding Amakusa, including the Ariake Sea, Yatsushiro Sea, and the East China Sea, as well as sections displaying freshwater fish from around the world. Visitors can even peer directly into the ocean through underwater windows inside the facility.

The aquarium also offers a wide range of interactive experiences, such as feeding tortoises and sea bream, joining guided tours, and even taking part in a one-day zookeeper program. Among these, dolphin encounters are especially popular-you can enjoy activities like a trainer experience that feels like being part of a dolphin show, or wading into the shallows for the “Fureai Beach” dolphin interaction. Please note that these experiences require additional fees beyond the general admission ticket.

The aquarium is part of the larger Amakusa Pearl Garden complex, which also includes restaurants with ocean views, a specialty pearl shop, and souvenir stores offering local goods.