10 Hidden Hot Springs Where You Can Experience Japan’s Timeless Scenery

Founded in 1975, the Association to Protect Japan’s Secluded Hot Spring Inns began when 33 small mountain inns—so inconvenient that even buses didn’t run there—came together.
Today, more than 100 hot spring inns belong to the association, which introduces hidden onsen in Japan through guidebooks and its official website.

Yachi Onsen is a single-inn retreat surrounded by nature at the foot of Mount Hakkoda in Aomori Prefecture.
Its highlights include “ashimoto jifun” (hot spring water bubbling up from the bottom of the tub) and two baths with different spring qualities.
With a history of at least 400 years, it has long been beloved as a therapeutic hot spring inn.
Showa-retro guest rooms and its specialty char dishes are also part of its appeal.

This inn is designed for fully enjoying the great outdoors, with an open-air bath overlooking the Iya River up close and a terrace with a 180-degree view of the Iya Valley.
To reach the free-flowing open-air bath by the Iya River, you can take a dedicated cable car. Descending slowly down a cliff with a 42-degree slope while taking in the panoramic view feels like an attraction in itself. The two baths—Keikoku no Yu and Seseragi no Yu—sit in a setting that feels almost fused with the Iya River, with the sound of the stream as the perfect background music. The baths rotate between men and women daily, so staying overnight lets you enjoy both.

Niseko Yakushi Onsen Ryokan is one of the hot spring inns scattered across the Niseko Onsen area, and it has been known as a therapeutic hot spring since 1891.
This traditional inn sits in a forest surrounded by mountains. It was highly popular for its setting and its free-flowing hot spring water—also bubbling up from under the tub—until part of the building collapsed under the weight of snow.
It closed at the end of May 2014, and as of November 2025, it has not resumed operations.
The hot spring still flows, but because it is not managed, bathing is not recommended.

One of the most popular hot spring inns in Nyuto Onsenkyo, Akita’s signature hidden hot spring area.
Deep in the mountains, it looks like a hidden village of samurai. And for good reason: it was once a therapeutic retreat for the lord of the Akita Domain. The thatched-roof row house now used as guest rooms served as quarters for the guards when the second lord, Yoshitaka Satake, came here for therapeutic bathing.
Here you can enjoy four different hot spring sources—Shiroyu, Kuroyu, Nakanoyu, and Takino-yu—across eight baths, each with its own spring quality.

At Hoshi Onsen Chojukan, the main building, annex, and the bathhouse “Hoshino-yu” are designated as Tangible Cultural Properties of Japan.
Known for its modern architecture built in 1895, both the bathhouse and guest rooms have beautiful light and shadow, creating an atmosphere full of character.
Just to the left after you enter the inn is an irori hearth where travelers gather, warm themselves, and chat—a scene that feels like stepping back in time.
You can enjoy three bathhouses with distinct atmospheres: Hoshino-yu, Tamaki no Yu, and Choju no Yu.

A single-inn retreat tucked away in the deepest part of the Nasu Onsen area, scattered along the slopes of Mount Chausu-the only active volcano in Tochigi Prefecture.
One of its highlights is a rustic, spacious open-air bath created by damming a hot spring stream flowing from the mountain behind the inn.
Its free-flowing hot spring water is known as “Bijin no Yu” (beauty bath) for its high moisturizing properties.
Be sure to try the rare “shochu hot spring mix,” which preserves the flavor of the source water.

Okukinu Onsen, known as the last hidden onsen in the Kanto region, lies in the deepest part of Kinugawa Onsen—often called Tokyo’s inner retreat.
Set along the Kinugawa River and surrounded by primeval beech forest, Okukinu Onsen does not allow regular vehicles, so you’ll need to take a shuttle bus for guests or walk in.
In this remote area, four hot springs with different water qualities are scattered around: Kaniyu, Teshirasawa Onsen, Nikkozawa Onsen, and Hatcho no Yu.
Enjoy the seasonal scenery and free-flowing hot springs to your heart’s content.

Me no Onsen Oku-Yuzawa Kaikake Onsen is a “hidden onsen” that’s relatively easy to reach.
One of its signature features is “Megusuri no Yu,” a hot spring long known since the Edo period for helping with eye ailments.
Its free-flowing hot spring water is also a draw, with one of Japan’s top flow rates at 450-650 liters per minute.
At an elevation of 700 m, summers are cool enough that you won’t even need air conditioning.
Surrounded by mountains and a stream, it also offers a beautiful night sky.

Ryokan Sanga is located in Kurokawa Onsen in the remote Aso area—and even farther from the center of the onsen town itself.
In a “satoyama” landscape often considered part of Japan’s timeless scenery, this ryokan lets you spend unhurried time while enjoying seasonal views with the murmur of the Chikugo River as background music.
It has seven different hot spring baths, two of which are open-air baths set in nature.
There are also three private baths, so you can enjoy a variety of hot springs without leaving Ryokan Sanga.

A hot spring area in Matsumoto City, Shinshu, located near the center of Nagano Prefecture. These hot springs rise from the eastern slopes of Mount Norikura, a sacred peak and a famous scenic site in Japan, in a wild setting surrounded by deep forest and the Yukawa Valley.
In the Taisho era, it was praised in a long historical novel by Kaizan Nakazato as a “spectacle of five colors in dazzling brilliance,” bringing its name to nationwide attention. Since then, it has been beloved by many therapeutic bathers who come to escape the bustle, feel the changing seasons, and enjoy the blessings of nature.

To keep the water clean, it’s proper etiquette to rinse off and remove dirt before soaking.
If you visit a hidden onsen without showers, scoop hot water from the bath with a bucket and rinse yourself first (kakeyu) before entering.

Some people wrap a towel around themselves in the bathing area, but entering the bath with it is considered bad manners, so be careful. Many onsen also prohibit bathing in swimsuits.
If you really want to cover up, wear a “yuyami-gi,” a bathing garment designed to be worn in the hot spring.
However, some onsen also prohibit bathing while wearing a “yuyami-gi.”

At hot springs that are part of a water source area, using shampoo or body soap may be prohibited.
If there’s no shampoo or soap in the bath area, check with the ryokan staff before using your own.