WATCH: World's first onsen theme park opens in Japan

The world's first hot tub theme park has opened its doors for visitors in a sold-out event in the Japanese city of Beppu, Saturday.

"There are plenty of rides which include bathing unlike in a regular amusement park which don't have hot springs,' Sashihar, a volunteer at the park, said.

A video project showing hot tub rollercoasters had inspired the city's mayor, Yasuhiro Nagano, who said the fantasy would become a reality if the video got over a million hits, a figure it exceeded in just three days.

"It started from the video. The city made a commercial video and if it reached 1 million views, they promised to make something like this," explained Sashihar, a volunteer at the park.

"Then, many people saw it, so it became true. The city opened an account on the web to crowdfund it."

The aquatic amusements were funded by voluntary contributions, and 75,000,000 yen (S$920,000) has been pledged to date to actualise the vision.

The park's attractions include a hot spring slide, a duck race, roaming zombies and a variety of rollercoasters.

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