Caldea - Andorra
https://www.caldea.com/en/
This is what you get when you mix a spa with a theme park. It's big, it's exciting, it's not like any spa you've ever been to before!
Széchenyi Thermal Baths - Budapest
http://szechenyispabaths.com/
Close your eyes and think of a spa. Now open your eyes, because you are going to see something that you just couldn't imagine...it's old, it's huge, it's got a name you can't pronounce...oh, and it's glorious!
Blue lagoon - Iceland
https://www.bluelagoon.com/
This is the spa that even people who don't know much about spas know. It's epic, it's natural (geothermal), and it's every bit as amazing in real life as it is in pictures!