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Rewards for bookings through our official website

  • Coffee voucher redeemable at Coffeehouse Kigi
  • Late check-out at 11:00 (generally 10:00)
  • Soaking in the hot tub after check-out (on the day of the check-out)
  • 500 yen off for a consecutive nights stay after the 3rd night (per person)

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Radium hot spring of Kiya Ryokan

Efficacy of Kiya Ryokan’s hot springs

Under supervision of Angelika Moder, PhD, the efficacy of Misasa’s hot springs has been proven.

Angelika Moder

Misasa Onsen’s hot springs have the world’s highest radon concentration, and the health effects research shows that the ratio of residents in Misasa who are 90 years of age or older is 6 times more than the national average, and the incidence rate of cancer is less than half of the national average. Guests can stay in a healing environment and expect a preventative stay.

In 2012, Kiya Ryokan’s radium hot spring was proven to demonstrate health benefits under the supervision of Angelika Moder, PhD of Paracelsus Medical University (Austria.)

World-class effects of radon hormesis

World-class effects of radon hormesis

Radon gas emitted from radium ore in Misasa Onsen’s underground is dissolved in hot spring. By ingesting radon, a low dose radiation stimulates and revitalizes cells moderately, resulting in acceleration of metabolism, increase of immunity and improvement of natural healing power. This is called the effects of radon hormesis. 

About radium and radon

About radium and radon

Radium is an ore and radon is gas. Radon is the only gaseous substance among more than 200 kinds of radioactive substances in the nature. Radon emits weak radiation, stimulates human cells moderately and revitalizes them.

Radium rocks are said to have existed in underground of Misasa Onsen since the ancient times. Radon is emitted from the radium ores in the rocks, warmed up by the heat of magma far beneath the surface of the Earth, mixed with the underground water, then springs out as a so-called radium hot spring. Technically, it can be called a radon spring.

It’s in a gaseous form and exists in the atmosphere, near the source of the springs of course, and in the air on the Onsen town’s main street. One can ingest a small amount of radon from taking a walk.

Efficacy and spring quality

Effective improvement on cardiovascular diseases, atopic dermatitis and skin care.

Efficacy and spring quality

Besides abundant radon, compositions of Kiya Ryokan’s hot spring include sodium ions, chloride, and metasilicic acid (moisturizing ingredient.) In addition, the ph of water is neutral (7.2) and it is gentle for skin.

Humans have mucous membranes and cilia inside trachea that connects one’s throat and lungs to prevent foreign objects in the air to reach lungs. Along with a large amount of steam, inhaling components of Onsen will boost ciliary activity, according to the research by Okayama University Graduate School of Medicine. Therefore, one can expect improvement on cardiovascular diseases such as allergic rhinitis, pneumonia and asthma.

Also, according to the research conducted by Tottori University Faculty of Agriculture, when these compounds are absorbed through skin, skin’s barrier function is improved. This positively affects skin health. We highly recommend our hot springs to those who wish to see improvement on their cardiovascular diseases, atopic dermatitis and beautifying skin.

Spring quality
Weak radio active sodium - chloride spring
Increase immunity, improve natural healing power, enhance antioxidant effect, build cancer prevention power, higher effectiveness in pain relief and atopic dermatitis, improve stress reduction
Color of spring
Colorless and transparent
Temperature of the source of hot spring
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