Ryokan Masuya

箱根仙石原温泉 万寿屋旅館はこねせんごくはらおんせん まんことぶきやりょかん

Lodging

Day Use

Yes

Bathing & Water

OnsenYes

Uses natural hot spring water

Water treatment

Pure source-flow
from Article 18 disclosure
  • Added water
    No
  • Reheated
    No
  • Recirculated
    No
  • Disinfected
    No
  • Bath additives
    No

大涌谷温泉 蒸気造成混合泉 2号線(仙石原方面)、3号線(強羅方面)

Owakudani Onsen Steam-Generated Mixed Spring (Line 2 / Line 3)

Operated by · 万寿屋旅館

Mixed source

Acidic
+ Sulfate · Chloride

An acidic calcium sulfate-chloride spring generated from the volcanic steam of Owakudani. At pH 2.1 the water is sharp enough to sting slightly on contact, faintly milky-white and turbid, carrying a faint rotten-egg note of H₂S. It is well supplied with metasilicic acid at 157 mg/kg, leaving a thin silica film for noticeably smoother skin. It is served as untreated source flow — no dilution, heating, recirculation, or disinfection.

Source temperature
6.0°C
Hot
Tonicity
1.28g/kg
Hypotonic
Free H₂S
1.28mg/kg
Typical
Color
faintly milky-white turbid
Odor
faint hydrogen sulfide
Highlights
  • Ultra-acidic
  • High silica

Analyzed Sep 28, 2018·神奈川県温泉地学研究所·Cert no. 神奈川県知事登録第1号

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Дмитрий Ракин

1 year ago

Once again following the footsteps of onsen-rush in Hakone, reaping the benefits for the second year now. A small Showa-style ryokan in Sengokuhara, Hakone. When I arrived, it looked closed and I had to call the old man on the phone, but he opened up and let me in. They're open every day. Still 900 yen. One bath that you can lock. The old man says families can use it together as kashikiri. The water is excellent: classic acidic sulfur of upper Hakone. Temperature is a bit on the hot side, you can dilute it. And it's all 100% kakenagashi. An unexpectedly lovely and charming ryokan with a great bath. The room itself is bright with a large window opening onto a garden, so it's essentially a semi-outdoor bath. Upgrading my recommendation to "must-visit in Hakone." https://t.me/jp_onsen/34096

SM
Sergey M
1 year ago

173. Ryokan Masuya, Hakone Visited for day-use bathing for 900, asked for a towel and they included it in the same price. Day-use hours are 10:30 to 16:00. Old-school ryokan in the northern part of Hakone, the building has that old damp smell. It seemed like the bath was private (the old man said you could lock the changing room). One small indoor bath with whitish-gray water, lots of white calcium deposits. Good air inside, practically no smell from the water. Temperature felt just above 42. For fans of that old-school vibe combined with interesting water — recommended. Otherwise — can be skipped.