Takayu Onsen (高湯温泉) is a small hot spring resort town halfway up the slopes of Mount Azuma in Fukushima City. First developed around 400 years ago, the town now consist of about a dozen ryokan huddled near the entrance to the Bandai Azuma Skyline sightseeing road.
The town's celebrated hot spring water emerges from ten different springs around the town. The strongly acidic water is rich in hydrogen sulfide, which results in a slightly milky, blue water and a distinctive sulfuric smell. In order to maintain the high quality of the water, many ryokan channel it directly and unadulterated into their baths.
Many of the ryokan open up their baths to non-staying guests during the day for a small fee. The most famous bath among them is the historic Tamagoyu, a small wooden bath house with one pool each per gender. There is also a public bath house, the Attaka no Yu, and a free outdoor foot bath at the center of the small town.
There are 3-5 buses per day between Fukushima Station (West Exit) and Takayu Onsen. The one way trip takes about 30 minutes and costs 820 yen. Alternatively, a rental car may be more convenient especially if you also plan to visit nearby Mount Azuma. Rental car outlets can be found around Fukushima Station.