Yokokawa Onsen Nakanoya Ryokan

Nakanoya Ryokan is the sole inn of Yokokawa Onsen, tucked into the hills of the Satomi district in Hitachiota, Ibaraki Prefecture. Its origin legend dates to around 1057, when Minamoto no Yoshiie (Hachimantaro), on his way to subdue the northern provinces, is said to have found a hot pool here and healed his battle wounds within four days. The inn itself has roughly 200 years of history and is known as a spring linked to Yoshiie.

The water is a simple sulfur cold-mineral spring with a source temperature of about 12.9C and a pH of 10.1, among the most strongly alkaline in Ibaraki. It is one of Japan's rare naturally welling springs, prized as a beauty bath for its slightly slippery texture, and said to benefit neuralgia, rheumatism, women's ailments, gastrointestinal complaints and motor function.

The barrier-free building offers an indoor bath and a family bath, plus a low-temperature sauna and a tourmaline stone-bath (ganban'yoku). Day-use bathing is 600 yen for adults (9:00-21:00), 1,200 yen including the stone bath, with private-room rest plans and overnight stays serving local Satomi mountain cuisine.