The Ocean Dome – in Miyazaki, Japan – is known as the world’s largest indoor water park measuring 300 metres in length, 100 metres in width and having a retractable roof. The air temperature is always kept around 30 degrees celsius. It is listed in the Guinness Book of World Records as the world’s largest indoor water park.
Ocean Dome has its own flame-spitting volcano, crushed white marble “sand”, and it also boasts the world’s largest retractable roof, providing a permanently blue sky. Temperature, wind and humidity are closely controlled to provide an ultra-safe “sea-side” experience.
Every hour, the volcano erupts and the hi-tech wave machines start up, starting a few minutes of sanitized surfing. Entrance cost is US $50 per person, which seems especially expensive given that there is a free, natural beach only 300 meters away.