Since the Edo period, this onsen has been gushing out of the ground,The three most beautiful onsen for skin.Onsen containing everything overflow today. Souce-of-onsen free-flowing Gongen-no-yu.

Onsen

The only one selected as a national recreational onsen resort in Kanagawa Prefecture Ashinoyu Onsen.Onsen with excellent effects on the skin, etc.

The color of the spring water is unusual in that it is emerald green at first and turns cloudy white depending on the temperature. The onsen gushes out at a rate of 200 liters per minute and is completely free-flowing. The famous onsen that has been praised since the Edo period is available,
and You can still enjoy the same. A variety of drinks, including alcohol, are available in the lounge, free of charge.

Onsen Composition

All of the three major qualities of onsen for beautiful skin: sulfur spring, sulfate spring, and bicarbonate spring are Contains.

Our onsen water is a "sulfur spring" that is expected to remove sebum and dirt, and to promote blood circulation and metabolism.

Sulfate spring is expected to coat the skin, restore elasticity, moisturize, and be effective for arteriosclerosis, trauma, and itchy skin.

It is a rare onsen that contains all three major qualities for beautiful skin: a "bicarbonate spring" that dissolves sebum and makes skin smooth and beautiful like soap, and a "bicarbonate spring" that is expected to be effective against skin diseases.

The mildly alkaline nature of the spring water makes it soft to the touch and prevents irritation.

Onsen qualitySulfur containing - calcium, sodium, magnesium - sulfate, hydrogen carbonate spring (hydrogen sulfide type) (former name: Sodium bicarbonate - gypsum hydrogen sulfide spring), slightly alkaline, hypotonic, high temperature spring
efficacy Beauty skin, helps heal neuralgia, rheumatism, skin diseases, etc.
Onsen Information 100% free-flowing Onsen water
Gushing volume: approx. 300,000 L/day (approx. 200-250 L/minute) = approx. 1,500 bathtubs/day

How to take onsen

History of Onsen

The onsen in Ashinoyu is "Gongen-no-yu"

The history of the Hakone Ashinoyu onsen is long, dating back to the Nara period (710-794), more than 1,260 years ago.As the onsen of Ashinoyu is "Gongen-no-yu," the general public is not allowed to enter Ashinoyu, and of course, bathing and other activities are not permitted.In addition, the Gongen※ is said to have originated when it was used by court nobles, priests, and ascetics who made pilgrimages to the shrine.

Gongen: Hakone Sansho Gongen (now Hakone Shrine), built by Manmaki Shonin

Onsen resort for national recreation

The Ministry of the Environment (MOE) has designated these onsen resorts as suitable for mental and physical recuperation, recreation, and rest since 1954, based on Article 29 of the onsen law. As of October 2019, there are 80 designated sites throughout Japan.
Ashinoyu Onsen was designated as a National Recreational Onsen Resort in 2015.

The conditions specified are broadly divided into those related to the source and those related to the onsen resort.

ObjectiveMental and physical recuperation, recreation, and rest
At the source.Terms and Conditions The source must be a therapeutic spring with high efficacy. Gushing rate must be 0.5L/minute or more per onsen user. The temperature of the onsen must be at least 25 degrees Celsius.
To the onsen resortTerms and Conditions Surrounding landscape blessed with natural environment Environment as a recreational area, history, climate, culture Medical facilities and staff using onsen. Transportation, and Safety against disaster. * Onsen resorts with entertainment districts are excluded in terms of recreational areas, etc.

Large public onsen

Newly renovated spacious public onsen in 2023.

Free-flowing onsen water We do not heat, add water, or circulate water.

Onsen and our employees

Since June 1, 2020, our hotel has welcomed two certified onsen bathing instructors to our team. To elevate your experience of "Onsen" and "Travel," we've introduced the following enhancements:
Our staff now includes more qualified experts in onsen-related matters, covering health, onsen quality, and bathing techniques to enhance your stay.
Regular study sessions are conducted, offering opportunities for continuous learning and insights into the world of onsen.

Onsen One large public onsen for men and one for women.
Hours of Use Check-in from 0AM / 5 AM - 9:30 AM
Onsen Supplies Body soap / Shampoo / Conditioner / Cleansing gel / Lotion / Milky lotion / Shower cap

Private open-air onsen

In April 2019, five private onsen was opened. Free of charge for guests.

Our onsen is 100% free-flowing and enjoys the rich effects of our own hot spring water, which bubbles up from its own source. Families and couples can enjoy a blissful time of healing both body and soul in a relaxed atmosphere without worrying about being seen.

Hours of Use 3 PM - 11:45 PM / 7AM - 9:45 AM (Each session lasts for 45 minutes)
How to use Reservations can be made at the front desk after check-in.
Onsen Supplies Body soap / Shampoo / Conditioner / Dryer / Face & hand wash towels

Free-flowing hot spring water We do not heat, add water, or circulate water.

Private room source for private use open-air day-trip bathing

Play with the colors and scents of the season. A room with a spacious sofa and an open-air onsen with a view of the forest and soaking in nature's song. And a lounge break is available as a set. This is a new proposal for a standing spa.

Room charge: 8,800 yen / 1 or 2 persons Includes Drinks and bath towel. You do not need to bring anything with you.

Day trip onsen