Okazaki-so

Day Use

Yes

Water treatment

from Article 18 disclosure

Added water
No
Reheated
Not disclosed
Recirculated
No
Disinfected
Not disclosed
Bath additives
Not disclosed

下地獄5号泉・下地獄9号泉・下地獄16号泉混合泉

Shimo-jigoku No. 5 / No. 9 / No. 16 Mixed Spring

Mixed source

Sampled at mixing tank

黄

Sulfur

+ Chloride · Sulfate

Classification

Sodium Chloride-Sulfate spring

A blend of three Shimo-jigoku wells in Naruko Onsen, classified as a sulfur-bearing sodium chloride/sulfate spring. The wellhead runs at a scalding 87 °C and is delivered fresh-flow (kakenagashi) to both indoor and open-air baths. Carrying enough H₂S to fall into the sulfur-bearing family, the water has the characteristic rotten-egg note alongside a salty, mineral-rich body.

Source temperature

87.0°C

Hot

Tonicity

1.39g/kg

Hypotonic

Highlights