The 8 Craziest Onsens In Japan

In Japan, bathing in an onsen is a popular activity, taking advantage of the heat and minerals of natural hot spring water to rejuvenate the body and the mind. Onsens come in all shapes and sizes. They can be outdoor onsens fed by water rising from the ground, exposed to the air and the elements. They can be indoor onsens with piped springs, belonging to ryokans (traditional Japanese inns). They can be private onsens in one’s home, or large public bathing facilities filled with people.

But then there are some wildcards. The more unusual onsens can be unique for natural reasons, or as a man-made gimmick. There’s one onsen filled with freshly picked apples in Aomori, another in Beppu that involves being buried under volcanic sand. Some onsens are filled with monkeys, others are filled with red wine! Let’s take a closer look at some of the most unique and interesting onsens in Japan.

Sketch of the inside of Takegawara onsen in Beppu
Takegawara Onsen in Beppu

Volcanic Sand bathing in Kyushu

In the southern island of Kyushu in Japan, a unique form of bathing (if we can call it bathing!) has become popular. In places such as Beppu, Ibusuki and Sunaba, high geothermal activity makes their black sand beaches quite hot. Volcanic sand bathing is usually done in bathing centres set up along the coast. The bather first changes into a yukata, then lays down on the sand. An attendant spreads sand over them, providing a small umbrella for shade against the sun.

The sand gets very hot, around 50-55°C (120-130°F), so bathing is limited to just 10-15 minutes, listening to the soothing sounds of the waves just metres away. The heat leaves the body and mind feeling rested and rejuvenated. When the session is finished, bathers move to a standard water onsen (including yukata!) to remove the sand, followed by a shower, and a cold ice cream or drink.

Sand Bathing in Japan

Apple Onsen in Hirakawa

Aomori, in the north of Honshu, is known as Japan’s apple production hub. More than half of Japan’s apples come from this region, including the incredible, gigantic sekai ichi apple. Tourism in Aomori is all about apples, too; visitors can go apple picking in an orchid, take part in the apple blossom festival to see the beautiful flowers in bloom, or try local apple ciders. But there’s another apple-related activity as well – the apple onsen.

Located in nearby Hirakawa City, 45 minutes drive from Aomori, Minamida Onsen Hotel Apple Land offers the chance to enjoy a steaming hot onsen with a collection of bobbing red apples. The onsen has a pleasing, delicate apple scent, and the malic acid which is released from the apple skin is said to soften the skin and improve circulation.

Apple Onsen, Minamida Hotel

Bathing Macaques At Jigokudani Monkey Park

Not all onsens are for humans in Japan. One of the most iconic images of winter in Japan are the bathing macaques of Jigokudani Monkey Park. Eyes closed, grooming each other, the sight of bathing snow monkeys looks very relaxing. The snow monkeys learned the art of using an onsen to keep warm from humans in the 1960s, when the ryokan was first built.

The tradition was carried on amongst the snow monkeys, who now visit the onsen year-round, (though especially when it’s snowing during winter months). The monkeys have their own dedicated onsen, not far from the Ryokan, and anyone who is travelling in the Nagano prefecture can visit the adorable and endearing primates.

Japanese macaques bathing at Jigokudani Monkey Park

Kuroyu (Black Water) Onsen

Kuroyu is a traditional form of onsen which is remarkable for its natural black waters caused by minerals in the earth. It can be found at the Yumoro No Sato onsen in the city of Chofu, part of the Tokyo metropolis.

The black colour comes from humic acid, an organic acid derived from broken down plant and animal materials. When bathing in the humic acid, it reduces dry skin and soothes skin conditions such as eczema and dermatitis. The experience of bathing in a black onsen, watching your body disappear under the water is very strange to say the least. Yumoro No Sato also has a restaurant on site, and a small manicured gardens to admire.

Yumori no Sato black water onsen

Mud Baths At Beppu Onsen Hoyoland

Another of Beppu’s most relaxing onsens is the white mud onsen of Beppu Onsen Hoyoland. The milky-white mud of the onsen has a creamy consistency, and rubbing the mud on your skin as an exfoliant is said to have rejuvenating properties. There are indoor onsens separated by gender, and a large outdoor pool which is mixed (although men and women are separated by a bamboo railing).

Drawing of two women bathing in a mud hot spring in Beppu Japan
Mud bathing in Beppu Onsen Hoyoland

Red Wine Onsen (And Green Tea, And Coffee…)

While many onsen in Japan are rooted in tradition, etiquette and the benefits of what nature has on offer, others skew the other way into all-out novelty. The Yunessun Hot Springs and Spa in the city of Hakone covers all of these strange ideas, becoming something of a theme park.

The wine onsen is coloured in a strange beetroot-red colour, from the wine mixed in with the geothermal water. More wine is tipped into the bath at several points during the day. A huge wine bottle prop adds to the fun of this unusual onsen, that’s said to help rejuvenate the skin!

drawing of people bathing in a red wine onsen in Japan
Bathing in Red Wine at Hakone Kowakien Yunessun

Also on site is the coffee onsen, made with freshly brewed coarse coffee. The coffee in the water is thought to reduce fatigue. Even though the water is rich chocolate-brown, t he decorations of barrels and bags of coffee beans add to the aesthetic. Yunessun has plenty more for brave onsen-goers. A green tea bath is supposed to be good for blood circulation, and a sake bath is available too. It also has a cypress bath, saunas, and standard onsen pools.

Yumomi Water Beating At Kusatsu Onsen

In the onsen resort town of Kusatsu, there is a traditional technique to cool down the hot water of the baths. The waters are far too hot to bathe in, reaching between 51°C to 94°C (123°F to 201°F). In order to avoid cooling with cold water, which would dilute the minerals of the spring water, a technique called yumomi is performed. Combined with traditional music and dance, 10 women dressed in yukata use large wooden paddles to stir and beat the water. As air is mixed in throughout the ritual, the water cools down. Visitors can watch the performance, and even try their hand at using the paddle!

Drawing of women performing yumomi water stirring at Kusatsu onsen
Yumomi at Kusatsu Onsen

Kawayu River Onsen

Kawayu Onsen on the Kii peninsula, Wakayama prefecture, is known for its unusual location. Whereas almost all onsen are baths, this onsen is spread out over an entire flowing river. In fact, kawa translates to river, and yu to hot water.

There are a string of ryokans, hotels and minshukus along one bank, and forest on the other. While the river water is quite cold, digging a pit in the riverbed (or sitting in a prepared one) let’s the lovely hot water bubble our of the ground and to the surface. At Kawayu, bathing suits and sandals and recommended.

Drawing of people bathing in Kawayu river onsen Japan
River bathing at Kawayu Onsen


While the classic geothermal hot springs is still considered the gold standard for onsens in Japan, some of the speciality onsens have their own benefits. The great thing about onsens in Japan is that they come in all shapes and sizes. Some have traditional rituals associated with them; others are populated by snow monkeys; there are even weird and wonderful baths filled with red wine or coffee. Whichever onsen you choose in Japan, you’ll be sure to have a relaxing, enjoyable bathing experience. Just don’t jump in with the macaques!