What is an Onsen?

According to the 1948 Hot Spring Law, onsens are defined as natural hot water springs that are at least 77 degrees fahrenheit (25 degrees Celsius) or higher and contain a certain level of mineral content.

History

Throughout its history, onsens, Japanese hot springs, have played an important role in Japanese culture and society. Onsen is not just a means of relaxation and healing, but also a symbol of Japan’s natural beauty and cultural heritage. Onsens are a cornerstone of Japanese culture, etched into its history like the vivid calligraphy on an ancient scroll. Today, there are thousands of onsens throughout Japan, each with its own unique properties and characteristics.

After World War II to promote the development of onsen tourism and ensure the safety and quality of onsen facilities throughout Japan, the 1948 Hot Spring Law, or Onsenhou in Japanese, was established to regulate the management and operation of hot springs in Japan.

As we wade deeper into time, there is evidence from prehistoric times that our ancestors bathed in the natural hot springs that perforated the land during the Jomon period (14,000-300 BCE). Back then, onsen bathing was as much a part of life as eating. They were nature’s gift, a balm for sore muscles and a soothing salve for battle-weary souls.

During the Nara (710-794) and Heian (794-1185) periods, the waters of the onsen took on an almost sacred aura. Nestled near temples and shrines, these mineral-rich baths offered more than just cleanliness, they offered respite, healing, and a connection to the divine. It was the elite’s form of indulgence, a silent testament to their standing.

In medieval Japan, even the hardened samurais found solace in the curative powers of the onsen. Post-battle, the onsen became a place to rejuvenate, heal, and prepare for the next skirmish. This ignited the development of onsen towns, cradling an industry built on tranquility and healing.

The Edo period (1603-1868), an era known for its vibrant culture, also witnessed a blossoming in onsen culture. It was a hot spring renaissance, so to speak. The nation took a dip in onsen towns like Hakone and Atami, places that became synonymous with relaxation. The bath, once a place of healing, became a place of communal bonding and shared stories.

In the modern Meiji period (1868-1912), the veil of antiquity was lifted. Japan modernized, and with it, the onsen facilities. Yet the heart of the onsen remained, drawing in tourists, both domestic and international.

From bathing in nature’s rocky pools to soaking in high-tech, automated baths, Japan’s onsens are a tale of time. They are a story of the country’s evolution, her people’s resilience, their reverence for tradition, and their ability to adapt. They are a warm, inviting chapter in the island nation’s rich history, one that continues to be written, even today.

Why do people go to onsens?

Onsens in Japan are believed to have numerous health benefits due to the mineral content and thermal properties of the water (and there’s a list of the benefits in the section below). Many visitors are also drawn to the cultural experiences and relaxation in the natural beauty are often tied to visiting onsens. But to truly appreciate onsens like the Japanese, it helps to understand the art of Japanese bathing. There is a certain poetry to it that transcends the simple act of cleansing the body. In Japan, the ritual of bathing extends beyond physical hygiene, it is a rite of spiritual purification and an integral part of the country’s cultural identity.

The Japanese take the act of bathing very seriously. In fact, bathing is seen as an opportunity to cleanse not only the body, but also the spirit. This perspective on bathing is deeply rooted in the Shinto religion, which emphasizes the importance of purity and cleanliness. It is a reflection of the reverence for nature that permeates Japanese culture.

At the heart of this tradition lies the onsen, a term that refers to a natural hot spring and the bathing facilities built around it. Onsens are scattered throughout the country, each with its own unique characteristics and mineral compositions. For centuries, they have served as communal spaces for relaxation and rejuvenation, as well as places for healing ailments and connecting with the surrounding nature.

The onsen experience begins before one even enters the bath. The process of undressing, washing thoroughly at a low faucet, and finally stepping into the steaming water is conducted with the utmost care and respect. Bathing in an onsen is not just about soaking in hot water; it’s a ritual that demands mindfulness and an appreciation for the natural world.

The communal aspect of onsens is essential to their cultural significance. Stripped of clothing and the societal norms that come with it, bathers engage in an unspoken bond, one of vulnerability and shared human experience. This sense of unity is a powerful reminder of the importance of connection and harmony, values that are deeply ingrained in Japanese culture.

Each onsen has its own unique atmosphere, influenced by the surrounding landscape and regional customs. Some are nestled in the mountains, surrounded by snow-capped peaks and lush forests, while others are situated near the ocean, with stunning views of the coastline. The architecture of the onsen facilities often complements these natural surroundings, incorporating materials such as wood, stone, and bamboo to create a seamless connection between the built environment and the natural world.

The art of Japanese bathing is a testament to the beauty of simplicity and the power of connection. The onsen experience is one that encourages introspection and cultivates an appreciation for the world around us. It is a practice that has endured for centuries, evolving and adapting, yet remaining true to its core values of purity, harmony, and reverence for nature.

In a world that often feels chaotic and disconnected, the art of Japanese bathing serves as a reminder of the importance of slowing down, being present, and nurturing our relationship with the world around us. It is a celebration of the simple pleasures of life, a timeless ritual that transcends cultural boundaries and invites us to experience the beauty of shared human experiences.

Today, onsens are popular among a diverse range of people in Japan, who use them for a variety of reasons, including relaxation, therapeutic benefits, and socializing. Onsen culture is an integral part of Japanese society and continues to be an important aspect of Japanese life and culture.

What are the benefits of onsen bathing?

Onsens in Japan are believed to have numerous health benefits due to the mineral content and thermal properties of the water and many travel domestically and internationally to experience it for themselves. Here are some of the general health benefits of going to onsens in Japan.

Muscle and Joint Pain Relief: The heat and minerals in the water of onsens can help alleviate muscle and joint pain by reducing inflammation and increasing blood flow to affected areas.

Stress Reduction: The peaceful and relaxing environment of onsens can help reduce stress and promote relaxation, which can have a positive impact on overall health and well-being.

Improved Skin Health: The minerals in the water of onsens, such as sulfur, magnesium, and calcium, can help improve skin health by promoting cell regeneration, reducing inflammation, and increasing collagen production.

Improved Circulation: The heat and pressure of the water in onsens can help improve circulation by dilating blood vessels, which can help lower blood pressure and improve cardiovascular health.

Respiratory Benefits: The steam from onsens can help relieve respiratory conditions such as asthma and bronchitis by opening up airways and reducing inflammation.

Detoxification: The minerals in the water of onsens can help stimulate the lymphatic system, which can aid in the removal of toxins from the body.

In general, onsen bathing is believed to have a positive impact on overall health and well-being, with many people using onsens for therapeutic and medicinal purposes. However, it is important to note that the health benefits of onsens may vary depending on individual health conditions and the specific mineral content of the water in each onsen. It is always recommended to consult with a healthcare provider before using onsens for therapeutic purposes.

What are the different types of onsens?

Today, throughout Japan, there are many different types of onsens, each offering its own unique experience and atmosphere. Whether you prefer an outdoor or indoor onsen, mixed or gender-separated, there is an onsen in Japan to suit everyone’s preferences. Here are some of the main types:

Outdoor Onsens: Also known as rotenburo, these are onsens that are located outside and offer stunning views of the surrounding natural scenery.

Indoor Onsens: Also known as naeba or uchiyu, these are onsens that are located inside a building or a ryokan (traditional Japanese inn).

Mixed Gender Onsens: Also known as konyoku, these are onsens where men and women can bathe together. Mixed gender onsens are less common in Japan, but can still be found in some areas.

Gender-Separated Onsens: Also known as konyoku, these are onsens where men and women bathe separately. Gender-separated onsens are the most common type in Japan.

Day-Use Onsens: Also known as kashikiri, these are onsens that can be used for a short period of time, usually a few hours, and do not require overnight accommodation.

Resort Onsens: These are onsens that are located within a resort or a hotel complex and offer a range of facilities and services in addition to hot springs.

Community Onsens: Also known as sento, these are public bathhouses that offer hot water baths. Community onsens are more common in urban areas and are often used by locals for relaxation and socializing.
Cave Onsens: These onsens are located in natural caves or underground tunnels, offering a unique and memorable bathing experience.
Foot Onsens: Also known as ashiyu, these are hot springs that are designed specifically for soaking feet rather than the whole body. Foot onsens are often located in public areas such as parks and are a popular way to relax and rejuvenate after a long day of sightseeing.
Open-air Onsens: Also known as rotemburo, these are outdoor onsens that are typically located in natural settings such as forests, mountains, or riversides. Open-air onsens provide an immersive and natural experience that allows guests to fully appreciate the surrounding scenery while enjoying the hot springs.
Private Onsens: Also known as kashikiri-buro, these are onsens that are designed for private use and can be rented by individuals or groups for a specified amount of time. Private onsens provide a more intimate and personalized experience and are ideal for those who prefer more privacy.
Theme Park Onsens: Some theme parks in Japan feature onsen facilities as part of their attraction. These onsens are designed to offer a fun and entertaining experience, often featuring colorful decorations, water slides, and other amenities that are not typically found in traditional onsens.
Mixed-Bathing Onsens: Also known as kon’yoku-sen, these are onsens that allow both genders to bathe together in the same water. These onsens are relatively rare in Japan and are typically only found in certain regions.
Modern Onsens: Some modern onsen facilities feature more contemporary designs and architecture, with minimalist decor, high-tech amenities, and other modern touches that cater to younger generations.

What are the different types of onsen water?

The onsen waters in Japan are geothermal gifts from the Earth’s crust that teem with a potpourri of minerals, each bringing its own therapeutic charm to the bathing experience.

Like a veritable periodic table in bath form, there’s a symphony of mineral-rich waters that make up the onsens in Japan. Each type of onsen water has its own special composition, and it’s these minerals and elements that determine the healing properties of the bath. Let’s dip our toes into the most common minerals you’d encounter in a typical Japanese onsen:

Sulfur Onsen (Iousen): The waters in these onsens carry a distinctive smell reminiscent of hard-boiled eggs. But don’t let the aroma deter you. Sulfur is renowned for its therapeutic properties, especially for skin ailments and chronic bronchitis. After a dip, you might find your skin feeling smoother and more supple.

Salt Springs (Shokuen): No, we’re not preparing soup here. Salt springs are rich in sodium chloride, and they’ve got a salty taste to match. These are especially good for improving circulation and keeping your skin hydrated.

Acidic Iron Springs (Tetsu-sen): These baths have high iron content, giving the water a red or brown hue. While it might look like you’re stepping into a bath of iced tea, these onsens can help with anemia and some skin problems.

Aluminum Onsen (Myouban-sen): High in aluminum content, the waters of these onsens are considered helpful in treating skin ailments like eczema and atopic dermatitis. And don’t worry, the levels of aluminum are safe for bathing.

Radioactive Springs (Housha-sen): Don’t fret, the radioactivity in these springs is very low level, but it’s said to stimulate the body’s metabolism and cell activity. Bathing in these springs is believed to be beneficial for high blood pressure and arteriosclerosis.

Carbonate Springs (Tansan-sen): Abundant in bicarbonate and carbonate ions, these springs are recommended for burns and chronic skin diseases, and are said to help promote beautiful, glowing skin.

Chloride Springs (Enka-sen): Packed with calcium, sodium, and magnesium chloride, these onsens are ideal for treating burns, cuts, and peripheral circulation disorders. The waters of these springs tend to leave a salty residue on your skin as they dry, creating an insulating effect that helps to keep you warm.

Always remember, these benefits can vary, and it’s essential to consult with a healthcare provider if you have specific health concerns. In the meantime, relax and enjoy the bounty of Japan’s geothermal landscape. It’s a testament to the beauty and complexity of nature, and a cultural experience you don’t want to miss.

How are onsens formed?

Onsens or hot springs are formed through the interaction of water with heat from various sources in the Earth’s crust. The unique geological and geographical features of Japan make it an ideal location for the formation of hot springs. Here are some of the ways that onsens can be formed:

Volcanic activity: Many onsens are formed from volcanic activity. Magma and hot rocks heat groundwater, which rises to the surface as hot springs. Japan is located in the Pacific Ring of Fire, a region with high volcanic activity, which makes it a prime location for onsens.

Fault zones: Onsens can also be formed along fault zones where the Earth’s crust is broken and hot water can seep through. Fault zones can be found throughout Japan, particularly in regions where there is active seismic activity.

Geothermal heat: Some onsens are formed from geothermal heat, which is generated by the Earth’s internal heat. These onsens can be found in areas with high geothermal activity, such as hot spots or geysers.

Mountain springs: Some onsens are formed from natural mountain springs that are heated by the sun or geothermal activity. These onsens tend to have a lower temperature than other onsens and are often used for relaxation rather than therapeutic purposes.

Coastal hot springs: Some onsens are formed near the coast, where seawater seeps into underground volcanic rocks, gets heated up, and returns to the surface as hot springs. These onsens are often rich in minerals and are believed to have therapeutic benefits for skin conditions.

Man-made onsens: Some onsens are man-made and constructed using geothermal heat sources. These onsens can be found in urban areas or resorts, and may feature a variety of different pools or baths with different temperatures and mineral compositions.

Where are the Popular Onsen Destinations in Japan?

There are many popular onsen destinations in Japan, each with its own unique features and characteristics. Here are several of the most popular onsen destinations in Japan:

Hakone: Located near Mt. Fuji, Hakone is one of Japan’s most famous onsen towns. It offers stunning views of the surrounding natural scenery, including the iconic mountain, and is known for its high-quality hot springs.

Kusatsu: Kusatsu is located in Gunma Prefecture and is one of Japan’s most famous onsen resorts. The hot springs in Kusatsu are known for their high acidity and are believed to have therapeutic benefits for a range of health conditions.

Beppu: Beppu is located on the southern island of Kyushu and is one of Japan’s most popular onsen towns. It is known for its wide range of hot springs, including mud baths and sand baths, and is a popular destination for both Japanese and international tourists.

Noboribetsu: Located in Hokkaido, Noboribetsu is known for its volcanic hot springs, which contain sulfur and other minerals believed to have therapeutic benefits. It is also home to Jigokudani, or “Hell Valley,” a dramatic geothermal landscape with boiling mud pools and steaming vents.

Arima: Arima is located near Kobe and is one of Japan’s oldest onsen towns, with a history dating back over 1,000 years. It is known for its high-quality hot springs and traditional atmosphere, with many ryokan (traditional Japanese inns) and historic buildings.

Atami: Atami is located on the eastern coast of Japan and is a popular destination for those looking for a quick getaway from Tokyo. It offers a range of hot springs, including seawater baths, and is known for its beautiful views of the Pacific Ocean.

These are just a few examples of the many popular onsen destinations in Japan. Each destination offers its own unique experience and opportunity to relax and rejuvenate in Japan’s natural hot springs.

Best time to go to onsens

Onsens can be enjoyed anytime of the year. Each destination captures a different facet of Japan’s beauty during the different seasons, creating an enchanting backdrop for your onsen experience.The same onsen one enjoyed during summer may offer a completely different experience based on the time you visit. So here are some recommended onsen destinations to enjoy for each season.

Spring

Spring in Japan is a spectacle. The country shivers off the frosty embrace of winter and wakes up to the riotous beauty of cherry blossoms. The onsen, that quintessential Japanese experience, is not to be missed. Let’s wander through a few of the best onsen areas that blossom in the spring:

Hakone: Just a stone’s throw from Tokyo, Hakone is an idyllic retreat that’s flush with natural beauty. Springtime cloaks this region in a soft, cherry blossom blush, providing an enchanting backdrop for a soak. With a wide range of onsens to choose from, Hakone offers something for everyone.

Kinosaki Onsen: A charming onsen town in the Kansai region, Kinosaki is brimming with old-world charm. Stroll through the willow-lined streets, soak in the seven public baths, and savour the spring air. The cherry blossom season makes it all the more enchanting.

Beppu: Located on the island of Kyushu, Beppu is renowned for its geothermal activity. It boasts a variety of onsens and hot sand baths that cater to all tastes. As the cherry blossoms bloom, Beppu turns into a picturesque retreat that’s hard to resist.

Noboribetsu: This is Hokkaido’s most famous hot spring resort. Although Hokkaido is known for its winter splendor, spring ushers in a different kind of magic. The greenery paired with the relaxing onsens is a balm for city-weary souls. The Jigokudani or “Hell Valley” is a must-visit for its otherworldly geothermal landscape.

Izu Peninsula: A favorite among the Tokyo crowd for its proximity, Izu Peninsula has a wealth of onsens that enjoy views of the surging Pacific and blooming cherry blossoms. The coastal scenery and the warm onsen waters make for a soothing combo.

Ask AI this command by seasons.

Summer

Summer in Japan blends the warmth of the sun with the refreshingly cool waters of the onsen. Let’s embark on a journey to some of Japan’s prime onsen locations perfect for your summer sojourn:

Nagano: Nestled in the heart of the Japanese Alps, Nagano offers a cool retreat from the summer heat. Home to famous onsen towns like Shibu Onsen and Nozawa Onsen, it provides a serene backdrop for a rejuvenating soak, all while keeping you nestled in the bosom of nature.

Hakone: Again, this popular retreat near Tokyo earns its spot. Summer paints Hakone in vibrant shades of green, making the area even more enticing. Luxurious onsens with views of the verdant hills or Lake Ashi? Count me in!

Gero Onsen: In the summer, this quaint onsen town in Gifu Prefecture transforms into a verdant oasis. Gero Onsen is considered one of Japan’s three best onsens, and with the Hida River flowing through it, the town provides a soothing respite from the sweltering heat.

Niseko: Hokkaido’s summer is mild and pleasant, making it an excellent choice for a summer onsen visit. Known for its ski slopes, Niseko also boasts lovely onsens. Surrounded by panoramic views of Mt. Yotei and the surrounding countryside, this is relaxation at its finest.

Kusatsu Onsen: One of Japan’s most famous hot spring resorts, located in Gunma Prefecture, Kusatsu Onsen provides a refreshing escape from the summer heat. With its high altitude and unique sulfur springs, it’s a destination that blends wellness with the wonders of nature.

Fall

Autumn in Japan. The landscape is on fire, cloaked in hues of vibrant red, orange, and yellow. It’s a time for appreciating the ephemeral beauty of life. And what better way to do that than soaking in an onsen, as the leaves fall gently around you. Let’s explore some of the best onsen areas for your autumnal escape:

Nikko: Tucked away in Tochigi Prefecture, Nikko is an autumn lover’s dream. The stunning foliage of Nikko National Park combined with relaxing hot springs, like those at Yumoto Onsen, makes for an enchanting getaway.

Nyuto Onsen: Located in the wilds of Akita Prefecture, this collection of traditional ryokan onsens offers the rustic charm of the old world. Surrounded by a thick beech forest that comes alive with colors in the fall, it’s an experience straight out of a Japanese print.

Kinugawa Onsen: Near Nikko, this hot spring town sits along the Kinugawa River. The autumn leaves along the river gorge are a sight to behold. The onsens here provide a mix of traditional charm and modern comforts.

Kurokawa Onsen: Tucked away in the hills of Kumamoto Prefecture in Kyushu, this picturesque town offers a charming view of the autumn foliage. The open-air baths, known as rotenburo, are perfect for enjoying the crisp autumn air and vibrant colors.

Hakone: Can’t leave this classic out. Autumn breathes new life into Hakone, coloring its mountains with breathtaking foliage. After a day of exploring, unwind at one of the many onsens and take in the autumn vistas.

Arashiyama, Kyoto: While not strictly an onsen town, Arashiyama in Kyoto is home to several ryokans with private onsens. Its breathtakingly beautiful autumn colors and the iconic Togetsukyo Bridge make it a worthwhile retreat.

Winter

Japan in winter. The air turns crisp, the landscape is dusted with snow, and steam rises from the surface of onsens tucked into the winter wonderland. This is Japan at its most ethereal. Let’s journey through some of the best onsen towns to visit during this season:

Hakone: This gem just outside of Tokyo has a spot on every list, no matter the season. In winter, Hakone’s mountains are often capped with snow, creating a magical atmosphere that’s perfect for an onsen visit.

Noboribetsu Onsen: The “Hell Valley” of Hokkaido, as it’s known, is a geothermal wonderland. In winter, the steamy waters contrast sharply with the snow-covered landscape. A soak in one of Noboribetsu’s many onsens is the perfect way to stave off the winter chill.

Kusatsu Onsen: One of Japan’s most famous hot spring resorts in Gunma Prefecture becomes a winter paradise. The town’s large central hot water field, Yubatake, is a steamy spectacle against the snowy backdrop.

Zao Onsen: A skiing and onsen paradise, Zao Onsen in Yamagata Prefecture offers the best of both worlds. After a day of skiing, you can soothe your weary muscles in the sulphurous waters of the onsens. Plus, you get to see the ‘Snow Monsters’, the trees coated and distorted by heavy snow and ice.

Jozankei Onsen: This onsen town in the outskirts of Sapporo, Hokkaido is popular for its therapeutic hot spring waters and beautiful snowy landscapes in the winter. The Hoheikyo Onsen is a must-visit outdoor bath, tucked deep in a scenic mountain valley.

Nozawa Onsen: This place in Nagano Prefecture is a skier’s dream with its excellent powder and slopes. But even if you’re not skiing, you can still enjoy the village’s numerous public hot springs, quaint atmosphere, and stunning snowscapes.

Nyuto Onsen: Once again, this place in Akita prefecture offers a winter wonderland with rustic charm. Its snow-covered landscape and hot spring baths are straight out of a fairy tale.

Each of these destinations offers a different flavor, a different perspective. So, pick one, pack your yukata, and let spring in Japan wash over you.

How to take an onsen bath?

To help you fully enjoy the onsen experience while respecting the local customs, I’ve compiled a list of Onsen etiquette – the essential dos and don’ts of onsens.

Do:

Remove your shoes: Upon entering the onsen facility, you will find a designated area to take off your shoes. Remember to do so, as wearing shoes inside is considered impolite.
Cleanse before you soak: Before entering the bathing area, wash yourself thoroughly using the provided shower facilities. It is essential to cleanse your body from head to toe, ensuring that no soap or shampoo residue remains, as the onsen water is meant to be kept clean and pure for all bathers.
Use a small towel for modesty: Although onsens are generally enjoyed in the nude, it is customary to bring a small towel with you to cover your private areas as you move between the washing area and the bath. Once you’re in the water, fold the towel and place it on your head or the side of the bath to avoid contact with the water.
Tie up long hair: To prevent your hair from touching the water, tie it up or use a shower cap.
Be mindful of noise: Onsens are meant for relaxation and reflection, so be respectful of others by keeping noise levels to a minimum.
Respect the rules: Some onsens have specific rules and restrictions, such as separate bathing areas for men and women, or not allowing those with tattoos to enter. Be aware of these rules and adhere to them.

Don’t:

Wear a swimsuit: Onsens are typically enjoyed nude, and wearing a swimsuit can be seen as disrespectful. Embrace the vulnerability and shared human experience that comes with being naked among fellow bathers.
Enter the water with soap or shampoo: Make sure you have rinsed off all soap and shampoo before entering the onsen, as the water should remain clean and uncontaminated for all guests.
Submerge your towel: The small towel used for modesty should never be submerged in the onsen water. Keep it on your head or place it on the side of the bath.
Swim or splash: Onsens are not pools; they are places for quiet relaxation and contemplation. Avoid swimming or making excessive movements that might disturb the water or other bathers.
Take photographs: Respect the privacy of other bathers by refraining from taking photos or videos.
Drink alcohol excessively: Although some onsens may serve alcohol, it is important to drink responsibly and respect the tranquil atmosphere.

By following these dos and don’ts, you can fully embrace the beauty of the onsen experience while respecting the customs that have shaped Japan’s unique bathing culture. So, take the time to slow down, immerse yourself in the onsen’s healing waters, and appreciate the transformative power of this ancient and sacred ritual.