Amazingly huge. Called the world's biggest hot spring resort. This is like a waterpark that is open all year round. Spend hours in the bathing suit required mixed bathing pools and enjoy all the slides (rides sold at a seprate cost). There are play areas for children and, in the summer, a roof top outdoor pool. After all the fun there are two different themed bathing areas. One is Asian the other European. The water is from a hot spring source but I didn't really feel it. You go here for the slides and pools. Super fun and a must try for everyone.