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Sengokukogen Daihakoneichinoyu

仙石高原大箱根一の湯せんごくこうげんだいはこねいちのゆ

Lodging

Day Use

No

Bathing & Water

Natural onsen water

Uses natural hot spring water

Outdoor BathYes

Open-air outdoor bath

Indoor BathYes

Enclosed indoor bathing area

Capabilities

Private BathYes

Private bath available for day-use visitors or hotel guests to reserve

Mixed BathingNo

Shared bathing area for all genders

Policies & Services

KidsWith Conditions

Welcomes children and families

DiningYes

Restaurant or dining open to visitors (not just hotel meal plans)

WashingYes

Shower, wash stations, soap and shampoo provided

TowelsYes

Towels available to rent or borrow

Rest AreaYes

Relaxation space for after bathing

ParkingYes

On-site or nearby parking available

仙石高原開発株式会社 供給温泉(新姥子温泉)

Sengoku Kogen Kaihatsu Supplied Spring (Shin-Ubako Onsen)

Operated by · 仙石高原開発株式会社

Mixed source

Simple
Color
colorless and clear
Taste
tasteless
Odor
very faint hydrogen sulfide
Hot source · 61°CHigh silica
Known good for
  • Aches & jointsstiff shoulders
  • Smooth skindry, rough skin
  • Recoveryfatigue, stress

A blended supply source (Shin-Ubako Onsen) drawing from six wells across Motohakone and Sengokuhara. A genuinely hot natural source (61 °C at the wellhead, served to bathers at 42 °C), classified as a simple thermal spring — lightly mineralized at 478 mg/kg of evaporation residue, weakly alkaline, and gentle on the body. A faint hydrogen sulfide note carries through, and a generous 162 mg/kg of metasilicic acid leaves the kind of silica film that gives skin a noticeably smoother feel afterwards.

Sampled at mixing tank·Analyzed Jun 19, 2014·一般財団法人 北里環境科学センター·Cert no. 神奈川県知事登録 第2号

Explore the water

About

A ryokan in Hakone's Sengokuhara area, part of the Ichinoyu group. The indoor baths use clear, skin-gentle spring water; outside, a small rotenburo (open-air bath) in a Japanese garden runs kakenagashi (free-flowing, non-recirculated) and can be reserved privately at no extra charge. Dogs are welcome throughout, including during meals.

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Reserve or check availability on a booking site.

SM
Sergey M
2 years ago

176. Sengokukogen Daihakoneichinoyu, Hakone Day-use bathing should be 1400 with a towel set + the receipt lets you visit other Ichinoyu locations in Hakone for free that same day (I got into this one for free using the receipt). Day-use hours are 13:00 to 20:00. Based on a sign — it's a dog-friendly place. Location isn't very convenient. One indoor bath. Clear water, hot+ temperature. Good air inside. Worth visiting if you're doing the Ichinoyu receipt run or happen to be right next to it. Otherwise can be skipped.

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Last updated June 23, 2026