Kiya Rakusen Spring

Analysis Unverified
木屋 楽泉
Misasa's Radium Spring Rising Underfoot

Misasa Onsen is said to have been discovered some 850 years ago when a samurai who spared a white wolf was guided to the spring in a dream, and its name is linked to the belief that "by the third morning, ailments are healed." It is known for radium springs with some of the world's highest radon levels. Rakusen wells up naturally from the ground along the Mitoku River, and hot water rises constantly from the spring pocket at the bottom of the tub.

AI Generated
This source matches 2 spring types· Tap to switch
放
SPRING TYPE
Radium SpringRARE

Limited exposure to radioactivity can be beneficial to the body. Since ancient times, people in Japan have used radioactive springs for therapeutic effects. Taken into the body through the respiratory system, the spring's radioactive components are considered effective as pain relief for conditions such as gout and rheumatoid arthritis.

See features & indications▾
Bathing indications
Hyperuricemia (gout)Rheumatoid arthritisAnkylosing spondylitis
Definition :Contains radon at 30×10⁻¹⁰ Ci/kg (8.25 Mache units) or more.
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
7.3
Neutral
Acidic ← 07 Neutral14 → Alkaline
Upper bound of neutral (pH 7.5). Approaching mildly alkaline, the boundary where skin starts to feel smooth.
TEMPERATURE
75.0℃
Very Hot Spring
Near boiling, extremely hot. Requires substantial cooling or dilution.
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.).

232 Bq/kg

A rare radioactive spring where trace radiation absorbed via inhalation and skin is expected to stimulate cells (the "hormesis effect").

Metaboric acidSee detail
10.5 mg/kg

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

Metasilicic acidSee detail
98.8 mg/kg

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

Fluoride ionSee detail
3.7 mg/kg

A trace antibacterial component that keeps skin clean.

Bicarbonate ionSee detail
220 mg/kg

Softens dead skin cells for a silky bathing feel.

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
Usage status is unknown — Information from facility postings or official sites has not been confirmed. Please check with staff on site.
▸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
無色透明
Smell
無臭
Taste
無味
EFFECTS
Spring-specific indications (bathing)
Hyperuricemia (gout)Rheumatoid arthritisAnkylosing spondylitisCuts and grazesPeripheral circulatory failurePoor circulationDepressionXeroderma
General indications (bathing)
High blood pressure (mild)Autonomic 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)Undergoing radiation therapy, pregnancy (radioactive springs)
BATHING TIPS
AI Generated

With radioactive springs, breathing in the radon-rich steam is considered as important as soaking, so relax at the tub's edge and breathe slowly. The source is 75°C, so water directly above the vent or near the inlet can be very hot; check the temperature before getting in.

EFFECT STORY
AI Generated

With 232.0 Bq/kg of radon, this radioactive spring is traditionally associated with helping relieve pain, while 454.7 mg/kg of chloride may support a restorative warmth that lingers long after you leave the bath.

CAUTIONS
AI Generated

The source is hot, so beware of scalding water near the vent and check the temperature first; chloride springs warm you quickly, so avoid overlong soaks and drink water afterward.

※ See the analysis data below for detailed contraindications

ANALYSIS DATAView all analysis fields ▼

Source Info

Source name
Kiya Rakusen Spring
Spring type
含弱放射能 Sodium Chloride Spring
Source temperature
75℃
pH
7.3
Flow rate
51.6 L/min
Osmotic pressure
低張性

Analysis Document

Analysis date
2009-01-26
Analyst organization
財団法人鳥取県保健事業団

Cations

Sodium ion Na⁺
387 mg/kg
Potassium ion K⁺
9.0 mg/kg
Magnesium ion Mg²⁺
0.40 mg/kg
Calcium ion Ca²⁺
23.1 mg/kg
Aluminum ion Al³⁺
0.00 mg/kg
Manganese ion Mn²⁺
0.10 mg/kg
Iron(II) ion Fe²⁺
0.10 mg/kg
Lead ion Pb²⁺
not detected
Copper ion Cu²⁺
not detected
Cadmium ion Cd²⁺
not detected
Total cations
0.42 mg/kg

Anions

Fluoride ion F⁻
3.7 mg/kg
Chloride ion Cl⁻
455 mg/kg
Hydrogen sulfide ion HS⁻
0.00 mg/kg
Thiosulfate ion S₂O₃²⁻
0.00 mg/kg
Sulfate ion SO₄²⁻
106 mg/kg
Bicarbonate ion HCO₃⁻
220 mg/kg
Carbonate ion CO₃²⁻
0.00 mg/kg
Bromide ion Br⁻
1.0 mg/kg
Total anions
0.79 mg/kg

Undissociated Components

Arsenious acid HAsO₂
0.50 mg/kg
Metasilicic acid H₂SiO₃
98.8 mg/kg
Metaboric acid HBO₂
10.5 mg/kg
Total undissociated
0.11 mg/kg

Dissolved Gas

Free carbon dioxide CO₂
8.8 mg/kg
Free hydrogen sulfide H₂S
0.00 mg/kg
Total dissolved gas
0.01 mg/kg

Trace Components

Radon Rn
232 Bq/kg

Totals

Total dissolved substances
1.3 mg/kg
Component total
1.3 mg/kg
Evaporation residue
1.2 mg/kg

Usage

Usage status
Unknown

Indications & Contraindications

Bathing indications
Hyperuricemia (gout), Rheumatoid arthritis, Ankylosing spondylitis, Cuts and grazes, Peripheral circulatory failure, Poor circulation, Depression, Xeroderma
General indications
High blood pressure (mild), 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), Undergoing radiation therapy, pregnancy (radioactive springs)

Drinking

Drinkability
Not drinkable
FACILITY INFO
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
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Misasa Onsen Kiya Ryokan

From¥22,000/ person / night (tax incl.)
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✨ 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