Akoyu Onsen
Illustration photo — not a verified picture of this exact spot.
- Location
- Hakusan, Ishikawa, Japan
- Water type
- sodium chloride
- Temperature
- 41 °C
- pH
- 7.3
Water profile
Relaxing — deep, immediate muscle release.
Loaded with major ions — the essential minerals (Ca, Mg).
Dense, salty water — you float without effort.
Akoyu Onsen in Ishikawa Prefecture offers a saline and simple mineral combination—the saline component carrying the ancient marine sedimentary character of Ishikawa's coastal geology on the Sea of Japan, while the simple alkaline base provides the gentle, skin-softening warmth accessible to all bathers. The Sea of Japan coastline geology that underlies much of Ishikawa's lowland concentrates sodium chloride minerals in springs that retain heat exceptionally well—the quality called yudamari—making saline springs particularly valued in the cold winter months when the Japan Sea coast is battered by howling seasonal winds from the Siberian continent. This spring's mineral combination reflects Ishikawa's position as both a culturally refined province and a geologically interesting junction between volcanic highland and ancient sea-floor sedimentary geology.