Genuine free-flowing natural hot springs, Ryuo Radon Onsen.

Ryuo Radon Onsen has been selected as one of the top 100 hot springs in Yamanashi.
You can enjoy the natural hot springs that have been carefully protected since its opening in 1980, and the fresh radon hot springs born from a radon generator.
You can fully enjoy our 100% natural hot springs, which is said to be one of only 2% of all hot springs in Japan, coming directly out from the source, a thousand meters underground. Please feel the difference from circulating hot springs.

Genuine free-flowing natural hot springs, Ryuo Radon Onsen.

Characteristics of Ryuo Radon Onsen

Radon Onsen is a system in which radon gas, kept at a safe constant concentration, is sent to the bathtub by a radon generator, and is inhaled in the bathroom or absorbed through the skin during the bathing.
Our radon generator is one of the largest in size for 1,000 people, and it is also used for medical purposes with a concentration of 87 mache. It was produced at the headquarter of Radon Development Corporation, and it is excellent in terms of safety with no gamma rays, etc.

Characteristics of Ryuo Radon Onsen

Radon is the most powerful ionizing substance in nature. When an appropriate amount of radon is taken into the body through the skin or breathing in baths, the powerful ionizing effect is activated and warms your body to the core.
Radon is constantly volatilizing and disappearing, but our bathtubs are specially designed for radon inhalation to maintain a stable and high concentration of radon at all times.
Bathing in a natural hot spring, it takes 1-2 hours to feel warmed up, but in Ryuo Radon Onsen, you will be warmed up in a short bathing time of 10-15 minutes, and the sweating effect lasts longer than in a sauna. Please experience the inhaling hot springs.

Radon Onsen

Hot Spring Information

Spring quality
Sodium spring, Chloride spring, Hydrogen carbonate spring (therapeutic spring), Radon
Neuralgia rheumatism, High blood pressure, Diabetes, Asthma/Emphysema, Depression

For guests

Hours of use
After check-in to 8:30 the next day (night-light is on after 23:00)

Bathing on a day trip

Hours of use
10:00 to 23:00
Admission (including tax)
Adults (13 years old and over) 770 yen / Children (12 years old and under) 660 yen
Towel set 440 yen / Aloha muumuu 330 yen
You Tube
Radon Onsen


Hotel Facilities

A nostalgic hot spring facility with a Showa retro atmosphere

Our hotel is a hot spring facility that has been in operation since 1980, where you can enjoy the Showa retro atmosphere.
There are shops and a game corner in the passage to the hot spring baths. There are also vending machines and a rest area, so please enjoy a relaxing time.
Guest rooms are located on the 3rd to 5th floors.
We offer a variety of guest rooms from relaxing Japanese-style rooms to Western-style rooms with twin beds.

Free Wi-Fi is available
in all rooms

  • Hotel Facilities
  • Hotel Facilities
  • Hotel Facilities
  • Hotel Facilities

There are three types of guest rooms to suit your style.

Japanese-style room 32㎡
No bathtub/With toilet/Capacity 2-6 persons
Ideal for families and groups.
Japanese-style room 16㎡
No bathtub/With toilet/Capacity 1-3 persons (recommended for 2 persons)
Ideal for a family of 2 or 3 people.
Western Style Twin room 16㎡
No bathtub/With toilet/Capacity 1-2 persons
Ideal for couples.
Japanese-style room 32㎡ Japanese-style room
Japanese-style room 16㎡ Japanese-style room
Western Style Twin room 16㎡ Western Style Twin room



Delicious cuisine using seasonal ingredients

For meals, we offer Kaiseki cuisine using carefully selected ingredients according to the season.
We offer a high-grade plan with 11 items using premium ingredients from Yamanashi Prefecture and the brand salmon "Fuji-no-Suke," a standard plan with 9 items, and a light plan with 7 items that can be enjoyed even by the elderly.
For breakfast, we offer a light Japanese set meal.

High-grade Plan High-grade Plan
Standard Plan Standard Plan
Light Plan Light Plan
Breakfast Menu Breakfast Menu