Takatomo Inn

One of the most unusual baths in Naruko, Takatomo Inn has four different spring types across seven tubs. The signature mixed indoor bath is the kuroyu (黒湯, black spring), a dense, inky sulfur-sodium bicarbonate water with a powerful tar-and-oil aroma unlike anything else in the area. There's also a rare milky green sulfur bath. Not for the faint-hearted, but a genuine hot-spring experience.