Shionoyu Onsen

Nasushiobara, Tochigi, Japan

Location: Nasushiobara, Tochigi, Japan
Water type: sodium chloride
Temperature: 41 °C
pH: 7.3

Water profile

Thermicity

Sedative

41 °C

LowHigh

Relaxing — deep, immediate muscle release.

Mineralisation

Restorative

LowHigh

Loaded with major ions — the essential minerals (Ca, Mg).

Buoyancy

Effortless float

LowHigh

Dense, salty water — you float without effort.

SodiumChloruresBrome

Shionoyu Onsen is the saltiest hot spring within the celebrated Shiobara Onsenkyō resort cluster in Nasushiobara City, Tochigi Prefecture, situated off National Route 400 along the Kajima River valley and served by two ryokan inns and one hotel in a secluded ravine setting, accessible via the Shiobara branch road leading toward the highland of Takahara-yama. Shiobara Onsenkyō encompasses eleven distinct spring areas distributed along the Hokki River gorge north of Nasushiobara, and Shionoyu is positioned upstream near the junction for the Yappogahara highland zone and the Tochigi Prefectural Forest, making it a gateway to both thermal bathing and mountain recreation in the volcanic foothills of the Nasu mountain range. The intensely saline waters of Shionoyu Onsen produce the powerful warming sensation characteristic of Japan's strongest sodium chloride springs, making them particularly prized for cold-weather bathing within a long thermal tradition.

Insider tip — Shionoyu Onsen is one of the historic springs of the Shiobara resort district in Tochigi, where sodium-chloride water has been celebrated for its warming and skin-moisturizing effects for over a millennium. The name itself, meaning salt spring bath, reflects the pronounced salty character of the water. Maple and zelkova trees draped over the gorge create a stunning autumn display each November. Several small wooden bathhouses preserve the Meiji-era architectural style that once lined the entire valley.

Find hotels nearby →Tickets & activities →See the map & practical info →