Hirayu no Mori no Yu to Sawamizu to no Kongosen
Analysis VerifiedHirayu Onsen, nestled in the deepest reaches of Okuhida Onsen-go, is a historic hot spring town said to have been discovered by defeated samurai of the Takeda clan. Hirayu no Mori is renowned for its expansive open-air baths set within a vast forest, where guests can soak while gazing at the Northern Alps. It is the perfect retreat for those looking to escape the hustle of daily life, as well as couples and families seeking to rejuvenate tired bodies after hiking or sightseeing.
The bar length shows how abundant each component is compared to thresholds that make it "distinctive" (therapeutic spring standards, beauty spring criteria, etc.).
A trace component with gentle antibacterial and anti-inflammatory action.
The aroma typical of sulfur springs, with circulatory and antibacterial effects.
Absorbed through the skin to gently promote peripheral circulation.
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.
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.
This bicarbonate spring gently softens skin by dissolving old keratin, making it famous as a 'beauty water.' After bathing, pat dry with a towel rather than rinsing, to keep the beneficial minerals on your skin. As the water is supplied at a high temperature of around 54°C, choose a spot away from the inlet and ease in gradually. Start with 3–10 minutes per session and extend to 15–20 minutes as your body adjusts.
With a near-neutral pH of 6.7, this spring is gentle on the skin, while its abundant bicarbonate ions (639.9 mg/kg) emulsify and cleanse excess sebum for a noticeably smooth complexion. Chloride ions (132.0 mg/kg) provide excellent heat retention, benefiting those with cold sensitivity, poor peripheral circulation, and chronic joint pain. At 67.7°C, the high-temperature spring warms the body to its core, supporting fatigue recovery, improved digestion, and stress relief.
Bathing is not recommended for those with fever, serious heart, lung, or kidney conditions, or gastrointestinal bleeding. Elderly guests and those with high blood pressure should avoid water above 42°C and are advised not to bathe alone.
※ See the analysis data below for detailed contraindications
ANALYSIS DATAView all analysis fields ▼
Source Info
- Source name
- ひらゆの森の湯と沢水との混合泉
- Spring type
- カルシウム・ナトリウム・マグネシウム-炭酸水素塩・塩化物泉
- Source temperature
- 67.7℃
- pH
- 6.7
- Flow type
- 掘削による動力揚湯
- Osmotic pressure
- 低張性
Analysis Document
- Analysis date
- 2014-04-09
- Analyst organization
- 株式会社神岡衛生社
- Registration No.
- 岐阜県第3号
Cations
- Lithium ion Li⁺
- 0.70 mg/kg
- Sodium ion Na⁺
- 143 mg/kg
- Potassium ion K⁺
- 13.1 mg/kg
- Magnesium ion Mg²⁺
- 40.5 mg/kg
- Calcium ion Ca²⁺
- 125 mg/kg
- Aluminum ion Al³⁺
- 0.03 mg/kg
- Manganese ion Mn²⁺
- 1.5 mg/kg
- Lead ion Pb²⁺
- 0.00 mg/kg
- Strontium ion Sr²⁺
- 1.1 mg/kg
- Barium ion Ba²⁺
- 0.10 mg/kg
- Cadmium ion Cd²⁺
- 0.00 mg/kg
- Total cations
- 0.32 mg/kg
Anions
- Fluoride ion F⁻
- 0.40 mg/kg
- Chloride ion Cl⁻
- 132 mg/kg
- Hydrogen sulfide ion HS⁻
- 0.40 mg/kg
- Sulfate ion SO₄²⁻
- 131 mg/kg
- Bicarbonate ion HCO₃⁻
- 640 mg/kg
- Nitrate ion NO₃⁻
- 0.20 mg/kg
- Total anions
- 0.90 mg/kg
Undissociated Components
- Metasilicic acid H₂SiO₃
- 65.1 mg/kg
- Metaboric acid HBO₂
- 14.9 mg/kg
- Total undissociated
- 0.08 mg/kg
Dissolved Gas
- Free carbon dioxide CO₂
- 126 mg/kg
- Free hydrogen sulfide H₂S
- 1.0 mg/kg
- Total dissolved gas
- 0.13 mg/kg
Totals
- Total dissolved substances
- 1.3 mg/kg
- Component total
- 1.4 mg/kg
- Evaporation residue
- 0.93 mg/kg
Usage
- Heating
- No
- Dilution
- Yes（The hot spring water is diluted with mountain stream water due to high source temperature）
- Recycle / Filter
- No
- Additives
- No
- Disinfection
- No
Indications & Contraindications
- Bathing indications
- Chronic pain or stiffness in muscles and joints (rheumatoid arthritis, osteoarthritis, lower back pain, neuralgia, frozen shoulder, bruising, sprains and similar conditions in chronic phase), muscle stiffness due to motor paralysis, poor circulation, peripheral circulatory failure, gastrointestinal dysfunction (stomach heaviness, intestinal gas, etc.), high blood pressure (mild), impaired glucose tolerance (diabetes), dyslipidemia (mild), mild asthma or emphysema, hemorrhoid pain, autonomic instability, stress-related symptoms (sleep disorders, depression, etc.), recovery period after illness, fatigue recovery, health promotion; Cuts and grazes, peripheral circulatory failure, poor circulation, xeroderma, depression
- Contraindications
- Active phase of disease (especially with fever), active tuberculosis, advanced malignant tumors or cases with marked physical weakness such as severe anemia, severe heart or lung disease causing shortness of breath with slight exertion, severe kidney disease with swelling, gastrointestinal hemorrhage, visible bleeding, acute exacerbation of chronic disease
Drinking
- Drinkability
- Not drinkable
