Spa World in Osaka is like the Disneyland of onsen. It holds 5,000 people on multiple floors of awesomeness. The top floor has an extensive swimming pool area (where you wear suits) and there is a floor of restaurants, shops and lounging areas. The onsen are divided into floors, one Japanese, one European, accessible to different genders each month. This month, it was European onsen for the ladies. So, I spent the afternoon hopping between Greece, Atlantis, Spain (which randomly housed the cafe), and Finland. I experienced pools of all temperatures, wet saunas, dry saunas, herb saunas, salt saunas, herbal and salt baths. No clothing at all on this floor after the lockers, so you are essentially hanging out naked with hundreds of strangers. The oddest part was ordering tea in the cafe from a fully-clad staff member. For the Japanese, the onsen experience is so much part of daily life. People bring their friends, kids, entire generations getting clean and relaxed together. And a day pass is only $15.