If you’re searching for a truly unique hot spring experience in Japan, Shirahone Onsen in Nagano Prefecture deserves a spot on your bucket list. Famous nationwide for its milky white mineral waters, this “hidden spring” has a centuries-old history as a healing retreat.
Our stay at Yukawasou, a quiet riverside inn nestled past a suspension bridge, offered a tranquil escape into nature and tradition.
■Basic Information
| Address | 4196 Shirahone Onsen, Azumi, Matsumoto-shi, Nagano 390-1515, Japan |
| Phone | +81-263-93-2226 |
| Day-use Hot Spring | Not available |
| Official Website | Shirahone Onsen Tsuribashi no Yado Sansuikan Yukawaso |
Yukawasou
A Hot Spring with Legendary History
Shirahone Onsen is said to date back to the samurai era, when wounded soldiers and miners came here to heal. The spa’s name means “white bones,” reflecting the striking color of the mineral-rich water. Since the 17th century, this area has attracted people seeking not entertainment, but genuine healing—the local saying goes, “Bathe for three days and you won’t catch a cold for three years.”
Hidden Away in Nature
Reaching Yukawasou is an adventure in itself. The inn sits deep in the mountains, past the city of Matsumoto, and you cross a long suspension bridge to get there. Especially in winter, the landscape is magical and covered in snow—just be prepared if you drive in snowy conditions as the steep mountain roads can be challenging!
The surroundings are pure nature, with almost no buildings nearby. The inn itself blends modern style with Japanese tradition, offering a quiet, serene stay.
Simple Comfort in Every Room
Guest rooms are minimalist yet cozy, with futons laid out for easy napping and expansive views of the mountains.
- Each room has a fridge, heater, and private toilet.
- Sweets, like salted yokan (a Japanese jelly dessert), await as a welcome treat.
- No TV means undisturbed relaxation (and as of October 2023, it’s intentionally TV-free to help guests unwind).
- Air-conditioning isn’t needed—even in summer, the mountain climate keeps rooms comfortably cool.
The Star – Milky White Hot Spring Baths
Yukawasou features several spring-fed baths:
- One shared indoor bath
- One private indoor bath
- Three private open-air baths (one available only from mid-May to mid-October)
All baths use water from different local springs, famous for their high calcium and sulfur content. Over time, the hot water forms calcium deposits that turn the wooden tubs into works of art. Some have been in use for over 50 years, boasting beautiful white encrustation, truly unique to Shirahone Onsen.
- Main indoor bath: Spacious, with white mineral deposits covering the tub. Water temperature varies, so you can choose your favorite spot—from piping hot near the source, to easier soaking in the cooler area.
- Private indoor bath: Intimate and perfect for solo relaxation, with fresh spring water and dramatic white deposits.
- Private open-air baths: Larger baths offer scenic views of the mountains and forest. The famous “Hoo” bath is especially spacious, ideal for lengthy soaks. Depending on season, water temperatures are usually between 38–41°C (100–106°F); some baths are a bit cooler in December, which adds charm for fans of “lukewarm” relaxation.
“Hoo” bath
“Uriga” bath
Waking up to winter’s silver landscape and taking a morning snow-view bath is an unforgettable experience.
Local Cuisine – Nourishing Flavors of the Alps
Dinner is a highlight, celebrating the region’s produce and traditions:
- The house specialty is “milky white hot pot,” simmering local beef and vegetables in a broth made from the onsen water, Swiss Brown cow’s milk, and Shinshu miso—uniquely creamy and warming.
- Fresh salmon sashimi, delicate soba dumplings, and crispy tempura are stars of the meal.
- Grilled river fish (iwana) is local favorite.
- Pickled vegetables and Shinshu apples round out the menu, reflecting Nagano’s flavors.
Breakfast is beautifully plated and simple—highlighting local salmon and the famous onsen rice porridge (onsen-gayu), cooked with spring water for extra softness and flavor.
The Ultimate Retreat
Yukawasou’s attractions:
- Milky white, mineral-rich hot springs in historic baths
- Multiple private baths—open-air and indoor—for nearly uninterrupted soaking
- Tranquil, secluded mountain setting, perfect for digital detox
- Delicious cuisine using local mountain ingredients
Although nightly rates start from ¥22,000 (approx. $150), the experience—soaking in a rare “hidden spring” and dining on mountain delicacies—is worth every yen, especially for a special occasion or anniversary.
If you’re seeking an authentic slice of Japanese hot spring tradition, far from crowds and surrounded by pristine nature, Yukawasou at Shirahone Onsen is your perfect getaway.