A magnesium-calcium-sodium sulfate spring (41.8 °C), neutral and moderately mineralized at 3,332 mg/kg — settled, mineral-rich body without a heavy edge. A touch of metasilicic acid layers in a soft, slightly silky feel on the skin.
433. Aso Hinoyama Onsen Dondoko-Yu, Kumamoto
Super sento with natural onsen water for 660 yen in Aso. Operating hours listed as 11:00 to 22:00 (Mon-Fri) and 07:00 to 22:00 (Sat-Sun). They stamp the Kyushu 88 Onsen book. Bath photos from the internet are accurate. There's a restaurant, a shop, chill-out areas, table tennis, and a hyperbaric chamber.
1. Indoor zone. Two large rocks in the center, and the interior is done in a warm style — wood is used in the washing area, the baths inside are designed in a natural rather than industrial way, which is also pleasant.
1.1. First half of the main bath. Cloudy white-green water, temperature 43-44.
1.2. Second half of the main bath. Clear, slightly murky pale-green water, temperature 40-41.
1.3. Oval bubble bath. Clear, slightly murky pale-green water, temperature 38.
1.4. Sauna.
1.5. Cold bath.
2. Outdoor zone. Part of the ground is also nicely done: various rocks laid out with moss on them. Surrounded by trees — behind a fence, but the view is quite decent.
2.1. Large outdoor bath. Clear, slightly murky pale-green water, temperature 40-41.
2.2. Small outdoor bath with the old-timers. Cloudy white-green water.
Great cozy place. Highly recommended when visiting Aso.
