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.
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.