The aquarium's water supply is derived directly from the Fuji-yuusui (Fuji spring water) which maintains a near-constant temperature year-round.
The facility features a 'Double Aquarium' design where two tanks sit side-by-side to illustrate the difference between mountain stream habitats and lake habitats.
It maintains a focus on the masu salmon, a species indigenous to the Japanese river systems.
The building is designed with a low profile to minimize visual disruption to the view of Mount Fuji from the surrounding plateau.
The aquarium serves as a research center for the preservation of endangered freshwater fish species native to Yamanashi Prefecture.
The Yamanashi Prefectural Fuji-yuusui-no-sato & Mori-no-naka Aquarium is a specialized facility dedicated exclusively to freshwater fish native to the Fuji Five Lakes region and the surrounding mountain streams. It is recognized as one of the few freshwater-only aquariums in Japan, utilizing the natural spring water fed by Mount Fuji. The aquarium features a unique double-tank layout that allows visitors to view the same water source from both above and below the surface. Its architecture is designed to blend into the surrounding woodland environment of the Oshino village plateau. The exhibits are organized by habitat, showcasing species ranging from small mountain stream dwellers to larger lake-dwelling predators. Educational displays focus on the ecological significance of the local spring water systems.
The double-tank viewing area where you can capture the reflection of the display against the natural forest light.
Visit during the morning to observe the fish when they are most active during feeding cycles.
Allocate time to walk the surrounding park grounds, as the area is known for its clear spring ponds.
If you have children, look for the interactive 'touch pool' section designed to introduce local stream life.
Do not mistake this for a large-scale marine aquarium; there are no salt-water mammals or tropical coral reef exhibits.
Closed on Tuesdays (unless a national holiday falls on that day).
