Japan, an archipelago bathed in geothermal wonders, whispers secrets of relaxation amidst its verdant valleys and snow-capped mountains. Its natural hot springs, known as "onsen," are not just sanctuaries for tired muscles and weary souls, but windows into an ancient culture steeped in reverence for nature's healing power.

Japan is a country with many active volcanoes and has the highest number of hot springs in the world. There are over 27,000 sources of hot springs and the country has a well regulated system of onsens. Within this geographical and cultural peculiarities certain unique traditional health practices have evolved, prominent among which is Touji or onsen therapy.

Touji (literally ‘bath cures’) means the amelioration of symptoms through hot water. Another popular term ‘onsen therapy’ (onsen ryohou), denotes a detailed approach to health management through the use of specific onsen waters. Bathing methods in Japan are open air bath (rotenburo), waterfall shower (utase), buried in sand, mud (colloid, or packages) and steam baths (oiran).

In Japanese there is a saying ‘Yu jyuunichi’ meaning that the ideal period of stay in a hot spring resort is around ten days. The stronger the concentration of minerals and higher the temperature, the more intense the yuatari (initial aggravation of symptoms after taking a bath) is.

According to the Hot Spring Law (1948) (Law no. 125), a natural spring that contains over a defined amount of at least one of the 19 natural chemical components, or is over a temperature of 25C at its point of release, is officially considered an onsen.

Japan's hot springs, or onsen, offer more than just physical rejuvenation; they're a window into ancient traditions and social etiquette. To immerse yourself seamlessly, here's a guide to help you navigate the cultural norms:

Before You Dip

• Cleanliness is key: Shower thoroughly with soap and shampoo before entering the onsen. This ensures the water stays clean for everyone.

• Leave your clothes behind: Onsen are gender-segregated, and nudity is mandatory within the bathing area. Don't worry, towels are provided to cover yourself when walking around.

• Tattoo policies: Some onsen may have restrictions on tattoos due to their association with organized crime. If you have tattoos, inquire about the policy beforehand.

• Respectful silence: Onsen are places for relaxation and reflection. Keep noise levels to a minimum and avoid loud conversations.

• For instance traditional bathing at Hirosaki onsen is to pray at the Buddhist temple, holding a bamboo ladle, then drinking two to three sips of ‘holywater’ and sprinkling over the ailing body part. After recovery, the ladle is to be offered at the temple in gratitude.

Once Inside

• Follow the flow: Most onsen have specific bathing sequences. Start with a warm soaking pool to adjust your body temperature, then proceed to hotter pools gradually.

• Mind your space: Avoid splashing or directing jets of water towards others. Be mindful of personal boundaries and maintain a respectful distance.

• Towel etiquette: Use your small towel to cover yourself while walking around or sitting on benches. Avoid wringing it out in the pools.

• Head down, hair up: Don't submerge your towel or wash your hair with soap in the onsen. Rinse your hair before entering the pools and use designated showering areas with shampoo and conditioner.

After Your Soak

• Rinse off: Briefly shower again after soaking to remove any mineral residue.

• Dry discreetly: Use your large towel to dry yourself fully before venturing outside the onsen area.

• Respect for footwear: Wear designated sandals provided within the onsen area and avoid bringing street shoes inside.

Additional Tips

• Bring your own toiletries: Onsen typically provide soap and shampoo, but some prefer to bring their own.

• Hydrate: Drinking plenty of water before and after your soak is essential, especially as onsen can be dehydrating.

• Etiquette with locals: Observe how others behave and follow their lead if unsure about any aspect of the onsen experience.

• Relax and enjoy: Onsen are meant for rejuvenation and stress relief. Let go of worries, embrace the warmth, and immerse yourself in this unique cultural experience.

By following these cultural norms, you can ensure a respectful and enjoyable onsen experience for yourself and others. Remember, onsen are not just about the physical experience; they're about mindfulness, respect, and connecting with a deeply ingrained Japanese tradition.

Toyosu Senkyaku Banrai

Housing a total of 65 eateries and shops, and a 24-hour onsen and spa resort, Japan’s new onsen, Toyosu Senkyaku Banrai aims to draw 2.6 million visitors annually.

Tokyo Toyosu Manyo Club offers relaxing experiences at hot springs, stone saunas, etc. Hot spring water is trucked in daily from the famous, ancient Hakone Hot Springs and Yugawara Hot Springs.

No extra booking is needed to rest and sleep in a generously sized recliner in the relaxation room.

The hot spring area has an open-air bath and footbath with a view over Tokyo Bay as well as accommodation facilities, with water sourced from the famous hot spring regions of Hakone and Yugawara in neighboring Kanagawa Prefecture, according to operator Manyo Club Co.

Enjoy the Senkyaku Banrai foot bath garden on the 8th floor offers panoramic views of Toyosu, and is available to all visitors free of charge. Popular Koto City shops and eateries offer Edomae-style dishes such as sushi and eel.

Hakone, Kanagawa

Hakone's hot springs have been drawing visitors for centuries, from samurai warriors seeking solace to artists finding inspiration. Explore the historic Fuji Hakone-Izu National Park, where ancient volcanic activity birthed the Owakudani Valley, a geothermal spectacle of bubbling mud pools and fumaroles.

Hakone's waters boast a diverse mineral composition. Sulfur whispers promises of detoxification and joint pain relief, while silica serenades your skin with its hydrating and exfoliating magic. Iron dances with oxygen, potentially boosting energy levels, and magnesium soothes tired muscles, leaving you feeling revitalized.

Be mindful of sulfuric gases in Owakudani Valley. Stick to designated paths and avoid the eggs boiled in the hot springs, as they may contain harmful bacteria.

Secret Tip: Escape the crowds by visiting Tsubame Onsen, a hidden gem tucked away in the mountains. Enjoy open-air baths amidst the serene forest, with the faint scent of sulfur and stunning views of Mount Fuji on a clear day.

Best Time to Go: Autumn (October-November) paints the landscape in fiery hues, while winter (December-February) offers a magical snow-covered wonderland. Spring (March-May) brings cherry blossoms and pleasant temperatures, while summer (June-August) can be hot and crowded.

Arima Onsen, Hyogo

Nestled in the foothills of Mount Rokko, Arima Onsen boasts two distinct springs: Kinsui (Gold Water), rich in iron and sodium, and Ginsui (Silver Water), high in sulfates and radium. Both offer skin-softening properties and potential health benefits like improved circulation and pain relief. Its history stretches back to the 8th century, with emperors seeking solace in its warm embrace.

For a unique experience, visit the Kin no Yu, a traditional public bathhouse with separate gold and silver water baths. Immerse yourself in history and the therapeutic whispers of the minerals. Avoid weekends and peak tourist seasons to experience Arima's enchanting atmosphere in relative peace. Explore the charming town adorned with traditional wooden houses and enjoy a delicious kaiseki meal after your soak.

Note: The high concentration of iron in Kinsui can stain towels and swimsuits. Be mindful of this and bring dark-colored swimwear.

Best Time to Go: Autumn offers stunning foliage and comfortable temperatures. Winter, with its snow-covered landscapes, is also magical, but be prepared for colder weather. Spring and summer can be hot and crowded, but offer festive events and vibrant greenery.

Kusatsu Onsen, Gunma

Kusatsu Onsen is known for its hottest waters in Japan, reaching up to 55°C (131°F)! Kusatsu's waters are a potent blend of minerals. Its waters, nicknamed "Yubatake" (hot water field) for their steamy intensity, can reach boiling point. Don't worry, cooling channels and wooden tubs temper the heat, offering a thrilling yet invigorating experience.

Sulfur reigns supreme, promising detoxification, skin health, and potential relief from joint pain. Aluminum, iron, and metasilicic acid add to the symphony of benefits, promoting circulation, aiding muscle recovery, and leaving your skin feeling smooth. These acidic waters, rich in sulfur and alum, are believed to have healing properties for skin conditions and muscle aches.

Secret Tip: Venture beyond the main baths and explore the Yubatake, a unique district with wooden gutters transporting steaming water through the town. Enjoy a traditional Yubatake dango, a sweet dumpling steamed in the hot water.

Best Time to Go: Summer offers pleasant temperatures and vibrant festivals. Spring brings beautiful cherry blossoms, while autumn paints the landscape in fiery hues. Winter can be cold and snowy, but the sight of snow-covered onsen is magical. Immerse yourself in the "Yubatake Festival" held annually in January, where men in loincloths parade through town carrying torches to appease the water spirits. Experience the unique culture and vibrant energy of this renowned festival.

Kurokawa Onsen, Kumamoto

Nestled in a secluded valley, Kurokawa Onsen is a haven for those seeking a traditional onsen experience. Explore charming ryokans, each with its own unique hot spring source and atmosphere.

The waters here vary in mineral composition, offering a smorgasbord of potential benefits. Some springs are rich in sulfur and iron, while others boast silica and magnesium. Choose the one that best suits your needs and indulge in the mineral symphony.

Secret Tip: Rent a Yutaka, a traditional Japanese cotton robe, and stroll through the village, hopping between different onsen for a truly immersive experience.

Best Time to Go: Spring and autumn offer pleasant temperatures and beautiful scenery. Winter can be cold and snowy.

Nyuto Onsen, Akita

Nestled deep in the mountains of Akita, Nyuto Onsen is a cluster of traditional wooden ryokans (inns) surrounding steaming pools. Imagine soaking in milky-white waters under a blanket of snow, snowflakes melting on your face as the warmth seeps into your soul.

Nyuto's waters are rich in sulfur and metasilicic acid, promising detoxification, improved skin health, and joint relief. The low acidity makes them gentle on sensitive skin, perfect for a truly relaxing soak.

Secret Tip: Book your stay well in advance, as Nyuto Onsen is a popular destination with limited accommodation. Opt for a ryokan with a private onsen for the ultimate secluded experience.

Best Time to Go: Autumn paints the landscape in vibrant hues, while winter offers a magical snowscape experience. Spring and summer bring warmer temperatures and lush greenery, but be prepared for crowds.

Beppu Onsen, Oita

The "Hell of Beppu": Don't be fooled by the name! Beppu Onsen boasts eight distinct "hells" – geothermal wonders showcasing fascinating colors, textures, and even boiling mud. While not for bathing, they offer a glimpse into the volcanic heart of the region, adding to the unique charm of this onsen haven.

With over 2,000 hot springs, Beppu offers endless soaking possibilities. Try the Kamegawa Onsen, famous for its sand baths, or visit the Tsurumi Onsen, where you can bathe with friendly monkeys!

Secret Tip: Purchase a Yuttopia Beppu Pass for access to multiple onsen in the city, offering a diverse bathing experience.

Best Time to Go: Spring and autumn offer comfortable temperatures and beautiful landscapes. Beppu can be enjoyed year-round, but summer (June-August) can be hot and humid.

Kai Yufuin on the island of Kyushu

With tens of thousands of geothermal springs spread across the islands of Japan, it’s not surprising that onsen built to take advantage of these water sources are a deeply ingrained part of the culture. Traditionally, the structures are rustic yet elegant, constructed from hinoki wood, bamboo and washi paper.

But for the past decade, the renowned Tokyo-based architect Kengo Kuma has been designing luxurious modern versions, with the latest, Kai Yufuin, having opened on the semitropical southern island of Kyushu in the fall of 2022.

Owned by the hospitality group Hoshino Resorts, the property offers 45 rooms, including five stand-alone villas; elegant kaiseki meals (multicourse experiences that focus on seasonal ingredients); post-bath massages; and geothermal pools built from striking black-stained Japanese cypress, with views of Mt. Yufu in the distance. For those new to the practice, a hot spring concierge is on hand to explain the various benefits of the waters and teach guests how best to make use of them.

Are you traveling in other parts of Asia? Take a look at more hot springs in Sri Lanka, Bhutan, Nepal, Thailand, Malaysia, China, Indonesia, India, Japan, Philippines, and Vietnam.