Mikasa Onsen
- Location
- Mikasa, Hokkaido, Japan
- Water type
- sodium chloride
- Temperature
- 42 °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.
Mikasa Onsen is situated in Mikasa, a former coal mining city in central Hokkaido now famous as a geological heritage destination within the Mikasa Geopark, where exceptional fossil deposits have yielded ammonites, marine reptiles, and Cretaceous-era invertebrates that document the ancient seas which once covered the Hokkaido interior during the age of dinosaurs. The Hokkaido Museum of the Geological Survey of Japan in Mikasa displays these remarkable paleontological treasures and explains the geological history of Hokkaido's formation, making the city an unexpectedly fascinating destination for natural history enthusiasts. The onsen here provide mineral bathing in a city transitioning from coal-era industry to heritage tourism, offering a warm and welcoming experience in a community quietly reinventing its identity around the remarkable ancient marine fossils buried in the hills beneath its streets.