"One of Japan’s oldest onsen is located in the outskirts of Matsuyama in a labyrinthine Meiji-era complex with several baths, tatami mat relaxing rooms, and even an onsen for the imperial family, which you can tour but not soak in. The landmark three-story wooden bathhouse is said to be the inspiration for Studio Ghibli’s Spirited Away ."

"Kinosaki Onsen is a hot springs resort town known for its seven public baths, including quiet and traditional Mandara-yu and the more modern Ichino-yu. Meander through Kinosaki’s willow-lined, pedestrian-friendly streets, where you’ll find traditional Japanese inns serving fresh crab and Tajima steak."

"Sansou Murata On Japan’s smaller island of Kyushu, the towns of Yufuin and Beppu are known for their hot springs, or onsen . The Sansou Murata blends traditional and modern elements for those seeking a unique onsen experience, with old Japanese houses comprising the ryokan, or Japanese inn, brought in from the countryside around Tokyo. The twelve unique guestrooms have high wood-beamed ceilings and private soaking tubs. Dining options include traditional Japanese and casual soba noodles, plus roll cake and chocolates for dessert. Rates include two meals daily (served in your room or in a private compartment in the inn's restaurant) and as many thermal baths as you can handle."

"Noboribetsu Onsen & Jigokudani (Hell Valley) Part of Shikotsu-Toya National Park, Noboribetsu Onsen is a resort town with baths fed by around 3,000 liters (793 gallons) of water from the hot spring known as Jigokudani, or Hell Valley. It earns its nickname from the impressive plumes of sulfur-scented gas that escape from the area's volcanic rocks. A popular tourist attraction, the spring's therapeutic waters contain a range ofminerals—not only sulfur but also various salts andiron."

"Just 90 minutes from the Jikoundani , where Japanese snow monkeys soak in their very own onsen, this ryokan’s onsen is exclusive to overnight guests and divided into three minimalist chambers, each with decreasing amounts of light. The last is nearly pitch black, except for a dramatic crack of light that creates a sensory-deprived “in utero”-style soak."

"Kinosaki, a picturesque 8th-century onsen town fed by the thermal and willow-lined Otani-gawa River, is beloved by weekenders donning yukata and geta and who onsen -hop around the town’s seven historic hot spring baths. Nishumuruya Honkan, one of Japan’s best ryokan , offers an excellent private onsen overlooking the lush bamboo forests of the enveloping Tajima mountains."

"Open since 1923, this is one of Kyoto 's oldest bathhouses. The late hours (3 p.m.–1 a.m.) make it a great stop after a long day of walking (Fushimi Inari Shrine, anyone?). At ¥430 (around $3.75) per visit, this onsen won't break the bank any time soon, either. These are public baths strictly divided by gender, and in the Japanese tradition, all bathing and soaking is done in the nude. Visitors can choose from eight or so pools, most inside but a couple also in an open-air courtyard. Funaoka has bragging rights as the first onsen to install an electric pool, but it's not for the faint of heart—literally. Tiny shocks pulse through the water—therapeutically or painfully, you decide—and a sign clearly instructs visitors with heart problems to avoid that particular pool. Everything else is safe and pleasant for soakers ranging from their early 20s to late 80s."