Seagaia Ocean Dome indoor beach

The Seagaia Ocean Dome was the world's largest indoor waterpark, located in Miyazaki, Miyazaki, Japan. The Ocean Dome, which is a part of the Sheraton Seagaia Resort, measures 300 metres in length and 100 metres in width, and is listed on the Guinness World Records. It opened in 1993, and visitor numbers peaked in 1995 at 1.25 million a year. The Ocean Dome was officially closed on October 1, 2007.

The Ocean Dome sported a fake flame-spitting volcano, artificial sand and the world's largest retractable roof, which provided a permanently blue sky even on a rainy day. The air temperature was always held at around 30 degrees celsius and the water at around 28.

Entrance cost was ¥2600 per adult and ¥1600 for children, depending on the season.