Namarikawa Well No. 3

Analysis Unverified
鉛川 第3号井
Carbonated Salt Waters of the Namarikawa Hills

Yakumo Onsen lies in forested hills along the Namarikawa River on the Oshima Peninsula. Water from Namarikawa Well No. 3 is rich in bicarbonate and chloride and carries over 410 mg/kg of free carbon dioxide. It carries a faint scent of iron and is concentrated enough for mineral crystals to float on the surface. Slightly salty, it warms the body to the core while leaving the skin moist and smooth, suiting those who want a long, unhurried soak in mineral-rich water to the sound of the river.

AI Generated
This source matches 2 spring types· Tap to switch
炭
SPRING TYPE
Bicarbonate Spring
aka "美人の湯"

Sodium bicarbonate cleanses the skin of old keratin and excess sebum, leaving skin soft and smooth. Expect beautiful skin after bathing.

See features & indications▾
Bathing indications
Cuts and grazesPeripheral circulatory failurePoor circulationXeroderma
Drinking indications
Gastroduodenal ulcersReflux esophagitisImpaired glucose tolerance (diabetes)Hyperuricemia (gout)

※ Only at facilities permitted to serve drinking water. 200–500 mL/day recommended.

Definition :Primary anion: bicarbonate ion.
Source: 環境省「あんしん・あんぜんな温泉利用のいろは」(監修:日本温泉気候物理医学会) ↗Read full article
PH VALUE
6.3
Neutral
Acidic ← 07 Neutral14 → Alkaline
Neutral (pH 6-7.5) per Japan Ministry of Environment classification. The pH range gentlest on the skin, suitable for long bathing.
TEMPERATURE
47.2℃
Hot Spring
Quite hot. Often diluted with water for a comfortable bathing temperature.
KEY MINERALS

The bar length shows how abundant each component is compared to thresholds that make it "distinctive" (therapeutic spring standards, beauty spring criteria, etc.).

Metaboric acidSee detail
47.2 mg/kg

A trace component with gentle antibacterial and anti-inflammatory action.

Bicarbonate ionSee detail
1243 mg/kg

A "beauty spring" that gently emulsifies dead skin cells, leaving skin smooth after bathing.

Metasilicic acidSee detail
93.8 mg/kg

A natural moisturizer that leaves a hydrated feel on the skin.

Free carbon dioxideSee detail
411 mg/kg

Absorbed through the skin to gently promote peripheral circulation.

Magnesium ionSee detail
83.1 mg/kg

Transdermal absorption gently supports skin hydration and muscle relaxation.

CHARACTER · COMPOSITION PROFILE
1234StimulationBactericidalSkin BeautyHeat RetentionRelaxation

Scores are calculated from mineral analysis data based on the Mineral Spring Analysis Guidelines (Ministry of Environment, Japan). They are unrelated to facility atmosphere or service quality.

USAGE
HeatedNo
DilutedYes
RecycledNo
FilteredNo
DisinfectedNo
AdditivesNo
Diluted: 館内掲示『温泉の利用状況について』:加水あり(源泉温度が高いため)。
▸Note

The temperature, pH and component values shown here are based on the hot spring analysis (source). Actual values in the bath may differ depending on heating, dilution, recycling and filtration. Please check current usage status at the facility.

SENSORY TEST
Color
無色澄明
Smell
無臭
Taste
微カン味
EFFECTS
Spring-specific indications (bathing)
Cuts and grazesPeripheral circulatory failurePoor circulationXerodermaDepression
General indications (bathing)
High blood pressure (mild)Rheumatoid arthritisAutonomic instabilityInsomniaChronic pain or stiffness in muscles and jointsMuscle stiffness due to motor paralysisGastrointestinal dysfunction
Contraindications
Acute illness (especially with fever)Active tuberculosisMalignant tumorsSevere heart diseaseRespiratory failureRenal failureBleeding disordersSevere anemiaAny actively progressing illnessPregnancy (especially early and late stages)
BATHING TIPS
AI Generated

This concentrated water warms quickly. Pour water over yourself first, start with about five minutes, and rest between soaks. Iron may tint skin and towels reddish. Drink water after bathing.

EFFECT STORY
AI Generated

Its 671.6 mg/kg of chloride wraps the skin in restorative warmth, while 1,243 mg/kg of bicarbonate leaves it smooth, suiting chilly days or whenever you want to step out with silky skin.

CAUTIONS
AI Generated

Rich in minerals and very warming, so avoid lightheadedness from long soaks; those with heart or blood-pressure concerns should keep baths short.

※ See the analysis data below for detailed contraindications

ANALYSIS DATAView all analysis fields ▼

Source Info

Source name
Namarikawa Well No. 3
Spring type
Sodium-Calcium Bicarbonate and Chloride Hot Spring
Source temperature
47.2℃
pH
6.3
Flow rate
300 L/min
Flow type
動力揚湯
Osmotic pressure
低張性

Analysis Document

Analysis date
2011-12-19
Analyst organization
株式会社岸本医科学研究所
Registration No.
北海道第12号

Cations

Sodium ion Na⁺
501 mg/kg
Potassium ion K⁺
62.7 mg/kg
Ammonium ion NH₄⁺
not detected
Magnesium ion Mg²⁺
83.1 mg/kg
Calcium ion Ca²⁺
226 mg/kg
Aluminum ion Al³⁺
0.20 mg/kg
Manganese ion Mn²⁺
0.90 mg/kg
Iron(II) ion Fe²⁺
1.7 mg/kg
Zinc ion Zn²⁺
not detected
Lead ion Pb²⁺
not detected
Copper ion Cu²⁺
not detected
Cadmium ion Cd²⁺
not detected
Total cations
0.88 mg/kg

Anions

Fluoride ion F⁻
0.30 mg/kg
Chloride ion Cl⁻
672 mg/kg
Hydrogen sulfide ion HS⁻
0.10 mg/kg
Thiosulfate ion S₂O₃²⁻
0.10 mg/kg
Sulfate ion SO₄²⁻
128 mg/kg
Bicarbonate ion HCO₃⁻
1243 mg/kg
Carbonate ion CO₃²⁻
0.20 mg/kg
Total anions
2.0 mg/kg

Undissociated Components

Metasilicic acid H₂SiO₃
93.8 mg/kg
Metaboric acid HBO₂
47.2 mg/kg
Total undissociated
0.14 mg/kg

Dissolved Gas

Free carbon dioxide CO₂
411 mg/kg
Free hydrogen sulfide H₂S
0.60 mg/kg
Total dissolved gas
0.41 mg/kg

Totals

Total dissolved substances
3.1 mg/kg
Component total
3.5 mg/kg
Evaporation residue
2.3 mg/kg

Usage

Heating
No
Dilution
Yes(館内掲示『温泉の利用状況について』:加水あり(源泉温度が高いため)。)
Recycle / Filter
No
Additives
No
Disinfection
No

Indications & Contraindications

Bathing indications
Cuts and grazes, Peripheral circulatory failure, Poor circulation, Xeroderma, Depression
General indications
High blood pressure (mild), Rheumatoid arthritis, Autonomic instability, Insomnia, Chronic pain or stiffness in muscles and joints, Muscle stiffness due to motor paralysis, Gastrointestinal dysfunction
Contraindications
Acute illness (especially with fever), Active tuberculosis, Malignant tumors, Severe heart disease, Respiratory failure, Renal failure, Bleeding disorders, Severe anemia, Any actively progressing illness, Pregnancy (especially early and late stages)

Drinking

Drinkability
Not drinkable
FACILITY INFO
AI draft (unverified)
Official site
Room with private open-air bath
Available
About tattoos and onsen
Travelers with tattoos can still bathe comfortably in a private bath (Kashikiri) or a room with a private open-air bath.
Hours
Weekdays: 11:00〜20:00
Day-use hot spring hours. The facility closes at 8 PM.
Closed days: Irregular holidays (Open during Golden Week, Obon, and New Year holidays)
Transit
25 minutes by car from JR Yakumo Station (JR八雲駅). Take the Hakodate Bus (函館バス) bound for Esashi (江差) from JR Hakodate Main Line Yakumo Station (JR函館本線八雲駅), get off at Obokoso Iriguchi (おぼこ荘入口) and walk 15 minutes. Pick-up service available for 2 or more people (consult by the day before). 20 minutes by car from Yakumo IC (八雲IC).
Parking
Available (30-50 spaces, free, no reservation required)
Day use fee
¥600Adults (junior high school age and above) 600 yen, Children (elementary school age) 300 yen, Infants (6 years old and under) Free. Discount tickets available (Adults: 6 tickets for 3000 yen, 12 tickets for 6000 yen).
Facilities
Public BathOpen-air BathFree Rest AreaSouvenir ShopRestaurantBanquet HallVending MachinesWi-Fi
House rules
All guest rooms are non-smoking.
This information may change without notice. Please contact the facility directly for accurate details.
How Long to Stay (Toji)
Start with 2 nights / 3 days

Japan’s Ministry of the Environment notes that even a short stay refreshes you. For a full therapeutic cure, around 2–3 weeks is the guideline.

More on toji length
✨ The descriptions, catch phrases, and translations on this page are generated by AI (Claude). pH, temperature, and component values are OCR-extracted from the official analysis report. Learn more