Hiruzen Yatsuka Onsen Kaiyūkan
A day-use hot spring at the heart of the Hiruzen highlands in northern Okayama, 500–600 m up. Its great appeal is the open-air bath, where you feel the highland breeze and look out over Jersey-cattle pastures and the three Hiruzen peaks through the seasons — cool in summer, autumn colour, snow-viewing in winter. The alkaline simple water is gentle on the skin, and the facility covers the basics: main bath, jet bath, sauna and open-air bath. Adults ¥740, children ¥420; open 10:00–22:00 (until 21:00 December–March; last entry 30 minutes before), closed Wednesdays (next day if a holiday; open during Obon and Golden Week). About 20 minutes by car from Hiruzen IC or 60 minutes by bus from JR Chūgoku-Katsuyama Station. Combine with Hiruzen yakisoba, Jersey soft-serve and a drive toward Mt Daisen. 100 parking spaces.