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- Kasen-An Seni Onsen Iwa no Yu
Kasen-An Seni Onsen Iwa no Yu
Nagano Prefecture/HokushinExperience true relaxation by doing nothing at our hidden hot spring accommodation, where you can enjoy the beauty of the changing seasons.
A serene Onsen Ryokan, "Kasenen Senjin Onsen Iwa no Yu," nestled in the mountains of Suzaka City, Nagano Prefecture. A mystical place where you can experience the beauty of the changing seasons. The secret to its many repeat visitors lies in the philosophy of hosting travelers while the hosts themselves continue their journey of life, deepening their craft. Every aspect, from cuisine to design to hospitality, cherishes the connections between people. Some things remain unchanged through time, while others evolve with the times—all for the sake of people. Come and rejuvenate your mind and body at this one-of-a-kind, special retreat.
My first trip to Karuizawa with my mother! This Accommodation is famous for being hard to book, and we happened to find an available date, so we made a Reservation right away!! We drove there in a rental car, and from the moment we arrived, the staff’s warm hospitality made us feel truly welcome. Everything about the Accommodation was wonderful. There are four private Onsen baths that don’t require a Reservation, as well as a large public bath and a cave bath. Surrounded by trees, it’s an Accommodation where you can feel time passing quietly. I’ve stayed at many Hotels and Ryokans before, but this was the first time I experienced such outstanding hospitality—including the food!! It’s easy to see why so many guests return again and again!
kohmao 8/17/2026It was a wonderful Accommodation surrounded by greenery. Because we could take our time during meals, we ended up completely full, but it reminded me that this is how dining is meant to be enjoyed. The bath was also incredibly relaxing. The Accommodation itself offers very generous space per guest, creating a true sense of openness, and the beautifully maintained garden trees and the gentle sound of the river were wonderfully soothing. Above all, the staff’s warm, unpretentious hospitality made us want to return in a different season.
青蜻蛉 8/10/2026
Facilities and Services
See All- Hot spring
| IN | 15:00~19:00 |
|---|---|
| OUT | 12:00 |
| Number of rooms | 18 rooms |
| Pet | Not allowed |
| Your child | Permitted |
Photo
See AllIntroduction of the Accommodation





Our Property is a secluded retreat nestled in the countryside. We welcome you to experience an ideal harmony with nature. Upon arrival, please pass through the gate and proceed forward. As you continue, you will come across a bridge over the Senjin River. Enjoy the journey to our Property as part of your experience.






The well-equipped public space was created with the desire for you to enjoy encounters with thoughtfully designed areas.

Cave Bath 'Sennin no Yu'
"The 'Sennin no Yu,' connected to the men's and women's large baths, is a cave bath extending up to 30 meters. It is a mixed-gender bath, so please wear a bathing suit when using it. With a maximum depth of 1.2 meters, you can enjoy an adventurous experience."






Starting in 1989 as a single property in the mountains. The concept of "a truly relaxing property" remains unchanged, constantly creating new value. Enjoy the changing of the four seasons.
Facilities and Equipment of Accommodation
- The room
- Hot Springs & Baths
- Facilities & Services
- Meal
Basic Information
| Card information | VISA / MASTER / JCB / AMEX |
|---|---|
| Pets | Not allowed |
| Breakfast | There is no information about breakfast. |
| Your child | You can stay. |
| Room service | Available for use We accept requests until 10:00 PM. |
| Common amenities |
|
| Facilities and Features |
|
| Esthetic Massage | None |
| Fitness gym | None |
| Public Bath |
|
| Open-air bath |
|
| Private bath |
|
| Room with Onsen Indoor Bath |
|
| Spring quality and benefits | Mildly alkaline simple Onsen Relaxation effects, insomnia, neuralgia, cold sensitivity, fatigue recovery, cuts, abrasions, burns ※Regarding the notation of "Gensen Kakenagashi" |
| Sauna | None |
| Hot stone spa | None |
Reviews
- Rooms & Amenities4.86
- Facility4.89
- Hospitality & Service4.98
- Meals4.76
- Onsen & Bath4.94
- Satisfaction4.89
*Reviews that have been translated from Japanese.*
*Showing only reviews from 一休.com (Japanese) and Yahoo!トラベル.*
Access Information
Nagano Prefecture3159 Nirei, Suzaka City
TEL:+81-26-245-2453
Approximately 20 minutes via Route 406 from "Suzaka Nagano Higashi IC" on the Nagano Expressway towards Sugadaira Kogen.
- Parking Information
- Fee
- Free for guests
- Parking time
- ---
- Parking space
- No restrictions
- Number of parking spaces
- 30 cars available outdoor
- Valet service
- Unavailable
- Pickup and drop-off information
- Unavailable
Frequently Asked Questions
Please provide information about Open-air bath.
・Business Hours: 15:00~11:00 ・Hot spring: Available ・Free-flowing: Available ・Cloudy hot spring water: None ・Supplementary information: 100% natural hot spring (Heating)
What are the qualities and benefits of the hot spring water?
The spring quality and efficacy of the hot spring are as follows. ・Spring quality: Mildly alkaline simple Onsen ・Spring efficacy: Relaxation effects, insomnia, neuralgia, cold sensitivity, fatigue recovery, cuts, abrasions, burns
What kind of facilities and features are available?
There are the following facilities and features. Hot spring・Open-air bath・Free-flowing hot spring・Large public bath・Private bath・Room service
I would like to know the access information.
Approximately 20 minutes via Route 406 from "Suzaka Nagano Higashi IC" on the Nagano Expressway towards Sugadaira Kogen.
Is parking available?
・Fee: Free for guests ・Parking space: Length --- Vehicle width --- Vehicle height --- ・Number of parking spaces: 30 cars ・Valet Service: Unavailable
Please provide information about Room with Onsen Indoor Bath.
・Hot spring: None ・Free-flowing: None ・Cloudy hot spring water: None
Please provide information about Private bath.
・Business Hours: 15:00~11:00 ・Hot spring: Available ・Free-flowing: Available ・Cloudy hot spring water: None ・Supplementary information: 100% natural hot spring (Heating) There are a total of 5 private baths, each with a unique atmosphere. One of them is exclusively for guests staying at Senzantei. No reservation or additional fees are required. Towels and other amenities are fully provided in the bathrooms.
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