When I lived there, people recommended that I go to a place called Harbin Hot Springs, where they have natural pools of hot water. They also mentioned it was clothing optional but I didn't listen hard enough to that bit. Me, my future wife and an ex female room mate pile into the bus and drive to Napa Valley. Once we were there, we quickly found out that nobody was taking the clothing option. There was only one locker room. That was certainly a new experience for a innocent North Carolina boy.
The biggest problem was that they were all being Zen and waving around crystals when I was like "yeehaaa, I'm but naked in a giant hot tub with 150 naked people!!!!!" I was thinking beer and naked cannonballs and they were going on about Chakras