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Hidden Hot Springs Guide in Iwate Prefecture - 10 Secret Onsen Surrounded by Spectacular Scenery and Healing Waters

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Hidden Hot Springs Guide in Iwate Prefecture - 10 Secret Onsen Surrounded by Spectacular Scenery and Healing Waters

Iwate Prefecture is home to numerous hidden hot springs nestled in rich natural surroundings. From wild hot springs to historic secluded onsen with accommodation facilities, the mountainous areas around Hachimantai offer diverse hot spring experiences. Today, we'll introduce 10 locations that are particularly valuable as hidden hot springs.

1. Toshichi Onsen Saiunso (Hachimantai City, Iwate Prefecture)

Toshichi Onsen is known as the highest-altitude hot spring in the Tohoku region, located at 1,400 meters above sea level. Against the backdrop of Hachimantai's magnificent mountain ranges, the solitary inn "Saiunso" stands quietly. This hot spring has a history dating back to its discovery in 1930 and opening in 1931, and is currently a member of the Japan Secret Hot Spring Preservation Association.

Around the inn, there are 5 mixed-gender outdoor baths, 1 women-only outdoor bath, and additional outdoor baths exclusively for guests, making it truly a treasure trove of open-air hot springs. Particularly famous are the mixed outdoor baths where milky white sulfur springs bubble up, with natural hot spring water flowing directly from the bottom of the bathing pools. Women can bathe wearing special bathing attire, and large bath towels are also available for purchase.

In spring, you can enjoy bathing while viewing snow walls; summer brings cool highland breezes; and autumn offers beautiful milky white waters reflecting the fall foliage. You can even apply mud from the spring bed as a natural face pack, with expected skin beautifying effects.

  • Spring quality: Simple sulfur hot spring (hydrogen sulfide type)
  • Natural source flow
  • Bathing facilities: Indoor baths = 3, Outdoor baths = 6
  • Source temperature: 87.0°C
  • No water addition or heating
  • Day-trip bathing: Available (Adults ¥650)
  • Accommodation: Available
  • Operating period: Late April to late October

2. Kunimi Onsen Ishizuka Ryokan (Shizukuishi Town, Iwate Prefecture)

Located on the slopes of Mount Akita-Komagatake at 850 meters above sea level, Kunimi Onsen is famous for its rare emerald green hot spring waters. Since the Edo period, it has been called "Yakushi-no-Yu" (Medicine Master's Bath) and was used as a therapeutic bathing facility for the Nambu domain.

Ishizuka Ryokan is a member inn of the Japan Secret Hot Spring Preservation Association, with its quiet atmosphere surrounded by deep mountain forests embodying the essence of a hidden hot spring. The hot spring water displays a beautiful emerald green color that changes to lemon yellow or dark green depending on weather conditions and sunlight. This unique coloration is attributed to calcium carbonate and sulfur particles in the water creating Rayleigh scattering for blue hues, mixed with yellow from polysulfide ions.

Large amounts of hot spring deposits dance in the bathing pools, and the water is potable, though known for its highly distinctive taste. The springs are highly effective, making them a source of great pride for local residents.

Currently operating partially due to snow damage, confirmation of operations from spring 2025 onwards requires checking the official website.

  • Spring quality: Sulfur hot spring (hydrogen sulfide type)
  • Natural source flow
  • Bathing facilities: Indoor baths = 2, Outdoor baths = 2
  • Benefits: Chronic digestive disorders, chronic gynecological conditions, diabetes, liver disease, neuralgia, rheumatism, etc.
  • Day-trip bathing: Confirmation required
  • Accommodation: Confirmation required
  • Operating period: Mid-May to early November (confirmation required)

3. Namari Onsen Fujisan Ryokan (Hanamaki City, Iwate Prefecture)

This historic hot spring opened about 600 years ago and is known as the only hot spring inn mentioned in Miyazawa Kenji's fairy tale "The Bear of Nametoko Mountain." Fujisan Ryokan was established in 1841 (Tenpo 12) and is a long-established inn selected as one of the "New Top 100 Hot Springs of Japan," "Japan Hot Spring Heritage," and "Japan's Top 100 Hot Springs."

The main feature is the "White Monkey Bath" (Hakuen-no-Yu), approximately 125cm deep, famous for its unique bathing style where visitors stand while soaking. Hot spring water bubbles up from the bottom of the bathing pool, and the water pressure from the depth warms the body to its core. In 2024, a new "Nametoko Mountain Sauna" themed after Miyazawa Kenji was also added.

The inn has 4 bathing areas, all featuring 100% natural source flow. Even the water from showers uses source water, demonstrating thoroughness in providing the true essence of "100% natural spring water." The main building, constructed entirely of zelkova wood, exudes historical dignity and creates an atmosphere reminiscent of the bathhouse in "Spirited Away."

  • Spring quality: Simple hot spring, alkaline simple high-temperature spring
  • Natural source flow
  • Bathing facilities: Indoor baths = 3, Outdoor baths = 2
  • Source temperature: Approximately 57°C
  • No water addition, heating, or circulation
  • Day-trip bathing: Available (Adults ¥700)
  • Accommodation: Available
  • Operating period: Year-round

4. Geto Onsen Moto-yu Geto (Kitakami City, Iwate Prefecture)

Located deep in the mountains at 650 meters above sea level, Geto Onsen is a historic hot spring area believed to have been established about 850 years ago. It was ranked as the eastern ozeki (second-highest rank) in Edo period hot spring rankings and is currently recognized as one of Japan's "Top 100 Famous Hot Springs."

At Moto-yu Geto, visitors can enjoy 7 outdoor baths scattered along the Geto River. These are foot-fed natural spring baths where hot water bubbles up from the bottom or sides of each bathing pool. Each has different temperatures and spring qualities, including "Oyu," "Senki-no-Yu," "Shin-yu," "Taki-no-Yu," and "Me-no-Yu." "Oyu" is particularly popular with therapeutic bathers, and the open-air baths offer spectacular 360-degree views.

Along the path to the outdoor bath complex, therapeutic lodges, shops, and restaurants line both sides, creating a streetscape-like scene. While mixed bathing is the norm, detailed women-only hours are established, allowing female bathers to use the facilities with confidence. This is a seasonal hidden hot spring that closes during winter due to heavy snowfall.

  • Spring quality: Sodium/calcium chloride sulfate spring
  • Natural source flow
  • Bathing facilities: Indoor baths = 2, Outdoor baths = 7
  • Source temperature: Approximately 48-65°C
  • No water addition or heating
  • Day-trip bathing: Available (Adults ¥700)
  • Accommodation: Available
  • Operating period: Early May to early November

5. Matsukawa Onsen Kyounso (Hachimantai City, Iwate Prefecture)

Located at 850 meters above sea level surrounded by Hachimantai's virgin forests, Matsukawa Onsen has over 250 years of history and is known as a remote hot spring within Towada-Hachimantai National Park. The area is famous for its deep winter snow, when four-wheel-drive bonnet buses provide alternative transportation.

Kyounso is a member inn of the Japan Secret Hot Spring Preservation Association, characterized by its traditional farmhouse-style architecture. The source water is colorless and transparent but turns a beautiful milky white when exposed to air. The mixed outdoor bath and women-only outdoor bath offer views of the great outdoors through all four seasons, with autumn foliage being particularly spectacular.

The inn stays comfortably warm even in winter thanks to a geothermal heating system. Dinner features dishes made with local ingredients such as Iwate shorthorn beef, guinea fowl, and river fish raised in clear streams, with the signature "Guinea Fowl Hot Pot" being particularly popular with guests.

  • Spring quality: Simple hydrogen sulfide spring
  • Natural source flow
  • Bathing facilities: Indoor baths = 2, Outdoor baths = 2
  • Source temperature: Approximately 70°C
  • Water added for temperature adjustment
  • Day-trip bathing: Confirmation required
  • Accommodation: Available
  • Operating period: Year-round

6. Amihari Onsen Sennyo-no-Yu (Shizukuishi Town, Iwate Prefecture)

Located at the foot of Mount Iwate at 750 meters above sea level, Amihari Onsen is said to be "Iwate's oldest hot spring," discovered in the 8th century. Particularly famous is the mixed wild outdoor bath "Sennyo-no-Yu," where visitors can bathe while viewing a waterfall, and it's believed that Miyazawa Kenji also soaked in these historic waters.

"Sennyo-no-Yu" is located about a 5-minute walk from Kyukamura Iwate Amihari Onsen, down stairs leading to Yunosawa Valley through the forest. This hand-built rock bath was created by human labor in the 1960s at a waterfall location accidentally discovered by staff.

After exiting separate male and female changing huts, there is one bathing pool for mixed bathing. The sound of "Kame-taki" (Turtle Falls) echoes beyond the bathing pool, creating a wild outdoor bath where visitors can soak while viewing the waterfall up close. Bathing wear rentals are available, so women can use the facility with confidence.

The facility closes in winter when buried under snow, operating only from early May to early November as a seasonal attraction.

  • Spring quality: Simple hot spring, sulfur spring (hydrogen sulfide type)
  • Natural source flow
  • Bathing facilities: Outdoor bath = 1 (mixed)
  • Benefits: Atopic dermatitis, peripheral neuropathy, psoriasis vulgaris, etc.
  • Day-trip bathing: Available (Adults ¥500)
  • Accommodation: Kyukamura Iwate Amihari Onsen
  • Operating period: Early May to early November

7. Kintaichi Onsen (Ninohe City, Iwate Prefecture)

Located in the quiet mountain area of Ninohe City in northern Iwate Prefecture, this hot spring area is nationally known for its "Zashiki-warashi" (house spirit) legends. Particularly, "Ryokufuso" is popular as an inn where visitors might encounter zashiki-warashi, but the entire hot spring area maintains an attractive hidden hot spring atmosphere.

"Cadal Terrace Kintaichi," which opened in 2022, has brought new vitality to the hot spring district, providing comprehensive facilities including day-trip bathing, saunas, and cafes. Additionally, "Samurai-no-Yu Obonai" is highly rated not only for its cuisine and hot springs but also for the heartwarming hospitality of its young proprietress.

This quiet mountain hot spring area allows visitors to relax away from urban hustle and bustle.

  • Spring quality: Simple hot spring, chloride spring
  • Natural source flow
  • Bathing facilities: Varies by establishment
  • Day-trip bathing: Available (varies by facility)
  • Accommodation: Available
  • Operating period: Year-round

8. Ichinoseki Onsen-kyo Sukawa Onsen (Ichinoseki City, Iwate Prefecture)

Located at the border of Iwate, Akita, and Miyagi prefectures, Sukawa Onsen springs forth at a high altitude of 1,125 meters on the northern slopes of Mount Kurikoma. Among the Ichinoseki Onsen-kyo group, it's particularly known for its hidden hot spring atmosphere.

The strongly acidic spring water containing hydrogen sulfide offers abundant hot water volume and magnificent views. Visitors can enjoy distinctive bathing facilities including the "Thousand-Person Bath" and natural steam baths. The environment is surrounded by alpine plants and is popular with mountaineers.

Multiple accommodation facilities in the surrounding area each have their own unique sources. Day-trip bathing is possible, and visitors can enjoy hot spring hopping.

  • Spring quality: Acidic spring
  • Natural source flow
  • Bathing facilities: Varies by facility
  • Benefits: Skin conditions, rheumatism, neuralgia, etc.
  • Day-trip bathing: Available
  • Accommodation: Available
  • Operating period: Year-round

9. Hachimantai Onsen-kyo Shin-Appi Onsen (Hachimantai City, Iwate Prefecture)

Hachimantai Onsen-kyo is the collective term for hot springs scattered throughout the Hachimantai area spanning both Iwate and Akita prefectures. Among these, Shin-Appi Onsen is one of the relatively unknown hidden hot springs.

Around Hachimantai, characterized by its gentle silhouette, visitors can stay active year-round with mountain climbing in spring, trekking in summer, and skiing in winter. The hot springs serve as the perfect place to heal fatigue from such activities.

Located at high altitude, the scenery is exceptional, with the nighttime sky being particularly spectacular. The experience of soaking in hot springs while gazing at a starry sky creates unforgettable memories.

  • Spring quality: Simple hot spring, sulfur spring
  • Natural source flow
  • Bathing facilities: Varies by facility
  • Day-trip bathing: Available
  • Accommodation: Available
  • Operating period: Year-round

10. Oshuku Onsen Choei-kan (Shizukuishi Town, Iwate Prefecture)

Oshuku Onsen, which springs forth in Shizukuishi Town, has a beautiful origin story: it was named after a bush warbler (uguisu) that was once seen healing its injured leg in the hot spring waters. Among the multiple inns in the hot spring district, Choei-kan is known as an establishment where visitors can enjoy 100% natural source flow hot springs.

The hot spring district features "Uguisu Yu-no-Sato Park," where visitors can enjoy free foot baths. Despite being relatively accessible, it maintains the atmosphere of a quiet mountain hot spring area, offering the experience of a hidden hot spring.

Visitors can spend leisurely time in a natural environment that shows different expressions through all four seasons. The autumn foliage season is particularly beautiful, attracting many hot spring enthusiasts.

  • Spring quality: Simple hot spring
  • Natural source flow
  • Bathing facilities: Indoor baths and outdoor baths
  • Benefits: Neuralgia, rheumatism, muscle pain, stiff shoulders, back pain, etc.
  • Day-trip bathing: Available
  • Accommodation: Available
  • Operating period: Year-round

Summary

Each of Iwate Prefecture's hidden hot springs possesses unique charm and represents precious hot spring resources. Many are located in high-altitude mountainous areas, allowing visitors to experience a sense of unity with nature that cannot be found in urban areas. With diverse forms ranging from wild hot springs to historic accommodation facilities, this area offers plenty to explore for hot spring enthusiasts.

Since many hot springs close during winter, we strongly recommend confirming operating status before visiting. Additionally, access to mountain hot springs can be affected by road conditions, so attention to weather and traffic information is necessary.

We encourage you to experience firsthand the hot spring culture nurtured by Iwate Prefecture's abundant natural environment.

※The information represents the most current available at the time of research, but there may be inaccuracies. Please confirm the latest information through official websites.