Unzen Onsen Seiunso

雲仙温泉青雲荘うんぜんおんせんせいうんそう

Own-source milky sulfur baths at a quiet Unzen ryokan

Lodging

Unzen Onsen

Kyushu & Okinawa·Nagasaki

0957-73-3273 seiunso.jp

Contact form

Day Use

Yes

11:00–18:00

¥880

¥2,500 for a private bath

Bathing & Water

Natural onsen water

Uses natural hot spring water

Outdoor BathYes

Open-air outdoor bath

Indoor BathYes

Enclosed indoor bathing area

Bathing Arrangements

Private BathYes

A private bath you can reserve for yourself or your group

Room OnsenNo

Private onsen bath in guest rooms, for overnight guests only

Mixed BathingNo

Shared bathing area for all genders

Standard gender-separated bathing; no mixed-bathing offering mentioned anywhere across the site, Google reviews or aggregator listings.

Policies & Services

DiningYes

A restaurant or dining room open to visitors, not only meals for overnight guests

Confirmed usable by a day-use (日帰り) visitor, not just overnight guests.

WashingYes

Shower, wash stations, soap and shampoo provided

TowelsYes

Towels to rent or borrow at the desk

ParkingYes

On-site or nearby parking available

Water treatment

Not disclosed

from Article 18 disclosure

Added water
Not disclosed
Reheated
Not disclosed
Recirculated
Not disclosed
Disinfected
Not disclosed
Bath additives
Not disclosed

雲仙温泉（小地獄）

Unzen Onsen (Kojigoku)

Operated by · 株式会社青雲荘

黄

Sulfur

Color: milky white, slightly turbid
Taste: slightly acidic
Odor: faint hydrogen sulfide

Calcium-Sodium Sulfate spring

pH 3.9Weakly acidicHot source · 64°CHigh silicaSulfur-rich

Composition fingerprint0.2 g/kg dissolved · Hypotonic

Ca²⁺26

Na⁺22

NH₄⁺17

SO₄²⁻90

◀ CationsAnions ▶

Calcium Ca²⁺: settling and calming; can leave a white mineral bloom.
Sulfate SO₄²⁻: "gypsum / Glauber's salt" — vessels and wound healing.

Known good for

Skin conditionsatopic skin, eczema
Circulationtired legs
Aches & jointsstiff shoulders

Sensitive-skin cautionbroken or dry skin

A simple sulfur spring of the hydrogen-sulfide type rising at Kojigoku in Unzen. At the source the water is milky and slightly turbid, with a faintly acidic taste and the characteristic rotten-egg note of H₂S. It is a weakly acidic, hot spring carrying 80.5 mg/kg of metasilicic acid, which leaves the skin smooth. The posted indications cover neuralgia, muscle and joint pain, sensitivity to cold and recovery from fatigue. Because the source temperature is high, fresh water may be added to cool it.

Sampled at wellhead·Analyzed Oct 29, 2009·財団法人佐賀県環境科学検査協会·Cert no. 佐環検温第24号

Explore the water

About

A ryokan in Unzen with its own hot-spring source, a rarity in this area. The outdoor bath sits within earshot of a mountain stream, and the indoor bath is a high-ceilinged room filled with milky white sulfur water. There's also a private (kashikiri) bath for families with small children. Guest rooms don't have their own tub, so all bathing happens in these shared baths. The inn sits a little apart from Unzen's main sightseeing streets, in a quiet, tree-covered spot.

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4.0

2 reviews

from 1 reviewer

Sergey M

2 years ago· edited

5. Unzen Onsen Seiunso, Unzen (Pt.1 - indoor and outdoor baths) ★★ A fairly modern ryokan, the bath entrance is on the first floor. For higaeri until 18:00, all baths are available, the indoor bath, access to a small outdoor bath, and a separate outdoor bath. The cost with a large towel rental is 1250 for everything. The water is milky blue, there is not much smell, the temperature is good, and it feels comfortable because of the oxygen. In the indoor bath there are several hollows for the body and head, where it is convenient to lie down and rest your head. Through the indoor bath you can go out to a small outdoor area, where there are two small baths, each for one person. The outdoor bath seemed similar in terms of the water, and is located on what feels like a large "balcony". Highly recommended. 25.12.2023

Sergey M

2 years ago· edited

5. Unzen Onsen Seiunso, Unzen (Pt.2 - private baths) ★★ For a day trip, for an extra fee you can use the private baths (¥2 500 for 50 min, one of two to choose from). Inside, they are different, the first is simpler, the second is more stylish and larger. But in the second one, the water is very hot, so it is not for everyone. Otherwise, it seems the water is similar. In both, the oxygen level feels comfortable. 25.12.2023