Guide
Ashizuri Kaiteikan is a unique underwater observatory located within Ryuguri Marine Park in Tosashimizu City, Kochi Prefecture. From the observation room situated approximately 7m below the sea level, you can observe the surrounding rich marine ecosystem. The structure is architecturally striking, featuring a white cylindrical tower and a red observation deck that extends out at the surface. The underwater observation room is equipped with 16 circular windows, protected by 45mm thick tempered glass, allowing visitors to see coral reefs, tropical fish, and various marine life up close.
The facility opened on January 1, 1972. The history of this site is quite notable; the original Shirohama Underwater Observation Tower was damaged during a tanker collision in 1985, leading to the construction of the current second-generation facility. The structure is recognized as a Registered Tangible Cultural Property of Kochi Prefecture, highlighting its architectural and cultural significance. Please note that due to the aging of the connecting bridge, the facility is scheduled to close for a preparatory period starting in May 2026 to ensure safety and prepare for future tourism needs. This facility has long played a vital role in preserving the local natural environment while serving as a key tourism resource.
The greatest highlight is the view from the underwater observation room. With 16 circular windows (60cm in diameter) positioned strategically, you can enjoy an unobstructed view of the seabed. Through these windows, you can witness vibrant tropical fish and schools of fish swimming among beautiful coral reefs. The architectural design is also a highlight: a 54m long connecting bridge leads from the shore to the tower, and the red cross-shaped observation deck adds a striking splash of color to the seascape. The journey through the facility is part of the fun, as you descend into the sea via a unique 64-step double helix staircase.
The clarity of the underwater view depends heavily on weather and light. On sunny days, sunlight penetrates deep into the water, making the colors of the coral and fish appear much more vivid. Therefore, we highly recommend visiting during the bright daylight hours. Additionally, the types of fish passing through the area change with the seasons, offering different marine spectacles depending on when you visit. Please be aware that the facility is scheduled to close starting May 1, 2026, due to bridge maintenance, so it is essential to check the latest operating status before your trip.
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