Table of Contents▾
What is Strontium ion?
Strontium ion (Sr²⁺) is a rare trace element with calcium-like properties. Its gentle astringent action tightens the skin.
Main Effects
- Calcium-like gentle astringent actionStrontium ions (Sr²⁺) bind with keratin proteins on the skin's surface. This process creates a mild astringent effect, which may help to gently firm and tighten the skin.
- Extremely rare in JapanFor an onsen to be noted for its strontium content, it must contain at least 10 mg/kg of strontium ions. This standard is defined in the Ministry of the Environment's Mineral Spring Analysis Method Guidelines, and very few hot springs in Japan meet this threshold.
- Often coexists with calcium ionsDue to their similar chemical properties, strontium is frequently found alongside calcium. It tends to appear in trace amounts in onsen waters that originate from seawater or have passed through limestone layers.
Strontium ion Top 5 Hot Springs
Top 5 hot springs registered on this site with the highest content.
RANKING BY THIS MINERAL CONTENT
Top 5 by Content
* Top 5 by mineral content matching the filters among onsen analysis records registered in this app
ANALYSIS REPORTS WITH THIS MINERAL
See onsen that contain this mineral
Onsen analysis reports visualized by minerals, pH, temperature, and a 5-axis profile. The carousel updates as you change the filters above.
Shijo Kawaramachi Onsen Soraniwa Terrace Kyoto Bettei
Salt content forms a protective barrier on the skin and prevents moisture and heat from escaping the body even after bathing. Boosts heat retention and has moisturizing effects.
See features & indications▾
※ Only at facilities permitted to serve drinking water. 200–500 mL/day recommended.
The Shijo Kawaramachi Onsen is a precious private source gushing from beneath Kyoto's most bustling district. It is lavishly used in the panoramic grand baths and guest room open-air baths at the "Soraniwa Terrace Kyoto" and "Bettei Kamogawa" hotels, which opened in 2022. Its greatest appeal is the ability to enjoy an authentic hot spring in a prime location for Kyoto sightseeing. This hypertonic chloride spring deeply soothes travel fatigue.
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.
Extremely rare in Japan. Calcium-like astringent action that tightens the skin.
Salinity comparable to seawater. The salt film traps heat for outstanding warmth ("hot bath spring").
Easily absorbed through the skin, helping to relax muscle stiffness during bathing — a transdermal nutrient unique to hot springs.
The Shijo Kawaramachi Onsen is a precious private source gushing from beneath Kyoto's most bustling district. It is lavishly used in the panoramic grand baths and guest room open-air baths at the "Soraniwa Terrace Kyoto" and "Bettei Kamogawa" hotels, which opened in 2022. Its greatest appeal is the ability to enjoy an authentic hot spring in a prime location for Kyoto sightseeing. This hypertonic chloride spring deeply soothes travel fatigue.
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.
Extremely rare in Japan. Calcium-like astringent action that tightens the skin.
Salinity comparable to seawater. The salt film traps heat for outstanding warmth ("hot bath spring").
Easily absorbed through the skin, helping to relax muscle stiffness during bathing — a transdermal nutrient unique to hot springs.
Kumihama Onsen Yumoto Kan
Salt content forms a protective barrier on the skin and prevents moisture and heat from escaping the body even after bathing. Boosts heat retention and has moisturizing effects.
See features & indications▾
※ Only at facilities permitted to serve drinking water. 200–500 mL/day recommended.
The Kumihama Onsen (Kouon Gensen) source emerges in the Kumihama Bay area, facing the Sea of Japan in northern Kyoto Prefecture. Drilled in 1992 from a depth of 1,500 meters, this source has since supplied local facilities like the "Kumihama Onsen Yumoto-kan." Its clear, colorless, and mild water is appealing to all. Loved as a spring that soothes travel fatigue in a scenic location overlooking a beautiful ria coast.
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 Kumihama Onsen (Kouon Gensen) source emerges in the Kumihama Bay area, facing the Sea of Japan in northern Kyoto Prefecture. Drilled in 1992 from a depth of 1,500 meters, this source has since supplied local facilities like the "Kumihama Onsen Yumoto-kan." Its clear, colorless, and mild water is appealing to all. Loved as a spring that soothes travel fatigue in a scenic location overlooking a beautiful ria coast.
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.
New Heartpia Onsen
Salt content forms a protective barrier on the skin and prevents moisture and heat from escaping the body even after bathing. Boosts heat retention and has moisturizing effects.
See features & indications▾
※ Only at facilities permitted to serve drinking water. 200–500 mL/day recommended.
The New Heartpia Onsen source is a pump-lifted hot spring located in Nagashima, Kuwana, an area famous for the Nagashima Resort. Despite being in a bustling leisure district, it offers an authentic onsen experience, drawing water from deep underground. This source exclusively supplies the Hotel Nagashima, available for both day-trippers and overnight guests, providing a peaceful respite to soothe bodies tired from nearby attractions.
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 New Heartpia Onsen source is a pump-lifted hot spring located in Nagashima, Kuwana, an area famous for the Nagashima Resort. Despite being in a bustling leisure district, it offers an authentic onsen experience, drawing water from deep underground. This source exclusively supplies the Hotel Nagashima, available for both day-trippers and overnight guests, providing a peaceful respite to soothe bodies tired from nearby attractions.
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.
Yoshiikeryokan
Salt content forms a protective barrier on the skin and prevents moisture and heat from escaping the body even after bathing. Boosts heat retention and has moisturizing effects.
See features & indications▾
※ Only at facilities permitted to serve drinking water. 200–500 mL/day recommended.
The Yumoto Onsen Mixed Spring (Registers 12, 72, 84, 89, 99, and 112) is a luxurious blend of six distinct sources gushing in the Hakone Yumoto area. Symbolizing the abundant waters of historically renowned Hakone, this spring generously supplies leading local inns, continuously soothing bathers with its stable and comforting mineral qualities.
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.
A trace component with gentle antibacterial and anti-inflammatory action.
The Yumoto Onsen Mixed Spring (Registers 12, 72, 84, 89, 99, and 112) is a luxurious blend of six distinct sources gushing in the Hakone Yumoto area. Symbolizing the abundant waters of historically renowned Hakone, this spring generously supplies leading local inns, continuously soothing bathers with its stable and comforting mineral qualities.
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.
A trace component with gentle antibacterial and anti-inflammatory action.
Ogawa Onsen
Salt content forms a protective barrier on the skin and prevents moisture and heat from escaping the body even after bathing. Boosts heat retention and has moisturizing effects.
See features & indications▾
※ Only at facilities permitted to serve drinking water. 200–500 mL/day recommended.
Ogawa Onsen is a naturally gushing thermal spring nestled quietly in the mountain villages of Toyama Prefecture, cherished by local residents for generations. This neutral-pH spring envelops the body in a gentle warmth, making it an ideal sanctuary for those seeking respite from daily fatigue or nursing cold sensitivities and digestive complaints.
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.
A trace component with gentle antibacterial and anti-inflammatory action.
Ogawa Onsen is a naturally gushing thermal spring nestled quietly in the mountain villages of Toyama Prefecture, cherished by local residents for generations. This neutral-pH spring envelops the body in a gentle warmth, making it an ideal sanctuary for those seeking respite from daily fatigue or nursing cold sensitivities and digestive complaints.
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.
A trace component with gentle antibacterial and anti-inflammatory action.
References
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