A trip to the finest hot spring town

Hot springs are a gift from Mother Nature, and the abundance of hot springs is another feature of the Izu Peninsula.

Hot springs are not unique to Japan, but are popular all over the world, and it is well-known that there were hot spring facilities in ancient Rome as well. In other countries, they are enjoyed more like a swimming pool than a bath.。

What are hot springs in Japan?

In Japan, there is a word for touji, and there is a long history of using hot springs for medical and health purposes.

Japanese hot springs are defined by a law called the Hot Springs Act, and many hot spring facilities display a list of hot spring ingredients. Hot springs have various characteristics such as the chemical ingredients, temperature, liquid properties (pH), color, smell, taste, and texture.

Hot spring quality can be classified into 10 types based on the types of chemical ingredients contained in the hot spring and their amount.

If a hot spring does not meet the standards for therapeutic springs, there is no name for the hot spring quality.

In the hot spring towns of the Izu Peninsula, you can bathe in 5 of the 10 types of spring quality classified in Japan.

Types of hot springs in Izu

Hot Spring Type	Criteria and Features
Simple hot spring	Hot springs have less than 1,000 mg of dissolved substances (excluding gaseous substances) per 1 kg of water, and the spring temperature at the time of gushing is 25°C or higher. Of these, hot springs with a pH of 8.5 or higher are called "simple alkaline hot springs." They are characterized by being soft to the touch, having no unpleasant taste, and causing little irritation to the skin. A characteristic of alkaline simple hot springs is that the skin feels "smooth" when bathing in them. For bathing: Autonomic nervous system instability, insomnia, depression.
Chloride spring	The amount of dissolved substances (excluding gaseous substances) in 1 kg of hot spring water is over 1,000 mg, and the main anion is chloride ion. Depending on the main cation, the spring is classified as sodium chloride spring, calcium chloride spring, magnesium chloride spring, etc. This type of spring is relatively common in Japan. Since the main component is salt, it tastes salty when drunk, and if the salt concentration is high or there is a lot of magnesium, it tastes bitter. For bathing: cuts, peripheral circulatory disorders, poor circulation, depression, dry skin For drinking: atrophic gastritis, constipation
Sulfate spring	The amount of dissolved substances (excluding gaseous substances) in 1 kg of hot spring water is over 1,000 mg, and the main anion is sulfate ion. Depending on the main cation, hot springs are classified as sodium sulfate springs, calcium sulfate springs, magnesium sulfate springs, etc. For bathing: cuts, peripheral circulatory disorders, poor circulation, depression, dry skin For drinking: biliary dysfunction, hypercholesterolemia, constipation
Iron-containing spring	Hot spring water contains 20 mg or more of total iron ions (iron II or iron III) per 1 kg of water. It is classified into bicarbonate and sulfate types depending on the anion. When hot spring water comes out and comes into contact with air, the iron oxidizes and the water turns reddish brown. It is also called women's hot spring because it promotes hemopoiesis. For bathing: anemia, kidney disease, gastrointestinal disorders, menopausal disorders, menstrual disorders For drinking: iron deficiency anemia
Sulphur Springs	Hot spring water contains 2mg or more of total sulfur per 1kg of water. Classified into sulfur type and hydrogen sulfide type, this type of spring is relatively common in Japan. The distinctive odor, similar to the smell of rotting eggs, is caused by hydrogen sulfide. For bathing: atopic dermatitis, psoriasis vulgaris, chronic eczema, epidermolysis For drinking: impaired glucose tolerance (diabetes), hypercholesterolemia

Izu hot spring town

Izu region	City	Hot Spring Town	Representative spring quality	Efficacy
伊豆北	Atami City	Izu Yugawara Onsen	Chloride springs	Neuralgia, rheumatism, women's diseases, gastrointestinal disorders, etc.
伊豆北	Atami City	Izusan Onsen	Sulfate springs	Neuralgia, rheumatism, wounds, burns, etc.
伊豆北	Atami City	Atami Onsen	Chloride springs	Rheumatism, women's diseases, skin diseases, cold sensitivity, etc.
伊豆北	Atami City	Ajiro Onsen	Chloride springs	Neuralgia, rheumatism, skin diseases, women's diseases, cold sensitivity, etc.
伊豆北	Mishima City	Takekura Onsen	Iron-containing springs	Neuralgia, anemia, high blood pressure, etc.
伊豆北	Numazu City	Tsuki no Yu Onsen	Iron-containing springs	Rheumatism, gout, wounds, high blood pressure, etc.
伊豆北	Numazu City	Mitsuhama Onsen	Alkaline simple springs	Neuralgia, joint pain, beautiful skin, etc.
伊豆北	Numazu City	Heda Onsen	Sulfate springs	Rheumatism, wounds, burns, skin diseases, etc.
伊豆東	Ito City	Usami Onsen	Simple springs, Chloride springs	Neuralgia, rheumatism, high blood pressure, fatigue recovery, etc.
伊豆東	Ito City	Ito Onsen	Simple hot springs	Neuralgia, rheumatism, fatigue recovery, etc.
伊豆東	Ito City	Jogasaki Onsen	Simple hot springs, chloride springs	Neuralgia, wounds, skin diseases, gynecological diseases, etc.
伊豆東	Ito City	Izu Kogen Onsen	Simple hot springs, chloride springs	Neuralgia, wounds, skin diseases, etc.
伊豆東	Ito City	Ukiyama Onsen	Alkaline Simple hot spring	Neuralgia, fatigue recovery, skin beautifying effects, gynecological diseases, etc.
伊豆東	Ito City	Akazawa Onsen	Simple hot spring	Neuralgia, muscle pain, joint pain, fatigue recovery, wounds, etc.
伊豆東	Higashiizu Town	Okawa Onsen	Chloride spring	Neuralgia, rheumatism, gastrointestinal diseases, wounds, gynecological diseases, etc.
伊豆東	Higashiizu Town	Hokkawa Onsen	Chloride spring	Neuralgia, rheumatism, gastrointestinal diseases, wounds, cold sensitivity, etc.
伊豆東	Higashiizu Town	Atagawa Onsen	Chloride spring	Neuralgia, rheumatism, skin diseases, gastrointestinal diseases, internal organ diseases, etc.
伊豆東	Higashiizu Town	Katase Onsen	Simple hot spring, chloride spring	Neuralgia, rheumatism, skin diseases, etc.
伊豆東	Higashiizu Town	Shirata Onsen	Simple hot spring, chloride spring	Neuralgia, rheumatism, gastrointestinal diseases, gynecological diseases, etc.
伊豆東	Higashiizu Town	Inatori Onsen	Sulfate spring	Neuralgia, rheumatism, gynecological diseases, skin diseases, etc.
伊豆東	Kawazu Town	Imaihama Onsen	Chloride spring	Neuralgia, rheumatism, skin diseases, women's diseases, wounds, etc.
伊豆東	Kawazu Town	Kawazuhama Onsen	Simple hot spring	Neuralgia, rheumatism, women's diseases, wounds, etc.
伊豆東	Kawazu Town	Yatsu Onsen	Chloride spring	Neuralgia, gastrointestinal diseases, wounds, hemorrhoids, etc.
伊豆東	Kawazu Town	Mine Onsen	Sulfur spring	Neuralgia, rheumatism, gastrointestinal diseases, etc.
伊豆東	Kawazu Town	Yugano Onsen	Salt Chemical springs, sulfate springs	Neuralgia, skin diseases, gynecological diseases, etc.
伊豆東	Kawazu Town	Kounabe Onsen	Chloride springs	Neuralgia, skin diseases, etc.
伊豆東	Kawazu Town	Otaki Nanadaru Onsen	Simple springs, chloride springs	Neuralgia, rheumatism, wounds, gastrointestinal diseases, etc.
伊豆南	Shimoda City	Shirahama Onsen	Simple springs	Neuralgia, joint pain, motor paralysis, health promotion, etc.
伊豆南	Shimoda City	Shimoda Onsen	Simple springs	Neuralgia, rheumatism Gusset, fatigue recovery, gynecological diseases, etc.
伊豆南	Shimoda City	Rendaiji Onsen	Simple hot spring	Neuralgia, rheumatism, muscle pain, frozen shoulder, etc.
伊豆南	Shimoda City	Yokokawa Onsen	Simple hot spring	Neuralgia, rheumatism, gastrointestinal diseases, lower back pain, fatigue recovery, etc.
伊豆南	Shimoda City	Kannon Onsen	Alkaline simple hot spring	Atopy, rheumatism, gastrointestinal diseases, lower back pain, muscle pain, etc.
伊豆南	Minamiizu Town	Shimogamo Onsen	Chloride Natural springs	Neuralgia, rheumatism, gynecological diseases, gout, etc.
伊豆南	Minamiizu Town	Yumigahama Onsen	Chloride springs	Neuralgia, muscle pain, fatigue recovery, etc.
伊豆西	Matsuzaki Town	Kumomi Onsen	Calcium chloride springs	Neuralgia, rheumatism, wounds, motor function disorders, etc.
伊豆西	Matsuzaki Town	Ishibu Onsen	Calcium chloride springs	Neuralgia, rheumatism, wounds, motor function disorders, etc.
伊豆西	Matsuzaki Town	Iwachi Onsen	Calcium chloride springs	Neuralgia, rheumatism, wounds, motor function disorders, etc.
伊豆西	Matsuzaki Town	Matsuzaki Onsen	Sodium sulfate springs	Neuralgia, rheumatism, chronic skin diseases, gout, etc.
伊豆西	Matsuzaki Town	Sakurada Onsen	Sulfate springs	Neuralgia, high blood pressure, arteriosclerosis, muscle pain, etc.
伊豆西	Matsuzaki Town	Osawa Onsen	Calcium sulfate springs	Neuralgia, rheumatism, gout, skin diseases, wounds, etc.
伊豆西	Nishiizu Town	Dogashima Onsen	Sulfate springs	Neuralgia, rheumatism, gynecological diseases, etc.
伊豆西	Nishiizu Town	Ukishima Onsen	Sulfate springs	Neuralgia, rheumatism, gynecological diseases, etc.
伊豆西	Nishiizu Town	Ugusu Onsen	Sulfate springs	Rheumatism, high blood pressure, etc.
伊豆中	Izu City	Shuzenji Onsen	Simple hot springs	Neuralgia, rheumatism, gastrointestinal diseases, etc.
伊豆中	Izu City	Yanase Onsen	Simple hot springs	Neuralgia・Rheumatism, motor dysfunction, neurosis, etc.
伊豆中	Izu City	Shiraiwa Onsen	Simple hot spring	Neuralgia, rheumatism, arteriosclerosis, high blood pressure, wounds, etc.
伊豆中	Izu City	Marunokogen Onsen	Sulfate spring	Burn, chronic skin disease, arteriosclerosis, etc.
伊豆中	Izu City	Umeki Onsen	Sulfate spring	Neuralgia, muscle pain, joint pain, frozen shoulder, burns, etc.
伊豆中	Izu City	Amagi Nikkatsu Onsen	Simple hot spring	Muscle pain, digestive disorders, fatigue recovery, etc.
伊豆中	Izu City	Yugashima Onsen	Sulfate springs	Neuralgia, rheumatism, chronic digestive disorders, wounds, etc.
伊豆中	Izu City	Sagasawa Onsen	Alkaline simple hot springs	Neuralgia, rheumatism, gynecological disorders, wounds, skin disorders, etc.
伊豆中	Izu City	Yoshina Onsen	Simple hot springs	Neuralgia, rheumatism, cold sensitivity, hemorrhoids, etc.
伊豆中	Izu City	Tsukigase Onsen	Arca Simple rheumatic hot spring	Neuralgia, rheumatism, high blood pressure, hemorrhoids, gynecological diseases, etc.
伊豆中	Izu City	Mochikoshi Onsen	Sulfate spring	Neuralgia, muscle pain, frozen shoulder, motor paralysis, bruises, etc.
伊豆中	Izu City	Funahara Onsen	Sulfate spring	Neuralgia, rheumatism, skin diseases, etc.
伊豆中	Izu City	Toi Onsen	Sulfate spring	Rheumatism, high blood pressure, arteriosclerosis, etc.
伊豆中	Izu City	Odoi Onsen	Chloride spring	Neuralgia, fatigue recovery, skin diseases, etc.
伊豆中	Izunokuni City	Ohito Onsen	Simple hot springs	Neuralgia, skin diseases, women's diseases, etc.
伊豆中	Izunokuni City	Izunagaoka Onsen	Simple hot springs	Skin diseases, rheumatism, women's diseases, nerve paralysis, etc.
伊豆中	Izunokuni City	Kona Onsen	Simple hot springs	Women's diseases, cold sensitivity, nerve paralysis, etc.
伊豆中	Izunokuni City	Nirayama Onsen	Simple hot springs	Neuralgia, rheumatism, muscle Muscle pain, joint pain, frozen shoulder, etc.
伊豆中	Izunokuni City	Komanoyu Onsen	Simple hot springs	High blood pressure, fatigue recovery, wounds, etc.
伊豆中	Izunokuni City	Nagoya Onsen	Simple hot springs	Neuralgia, gastrointestinal disorders, rheumatism, high blood pressure, etc.
伊豆中	Kannami Town	Hatake Onsen	Simple hot springs	Neuralgia, rheumatism, high blood pressure, diabetes, etc.
伊豆中	Kannami Town	Springs Onsen	Simple hot springs	Neuralgia, muscle pain, etc.