1
Kojigoku Onsen-kan

Full of hidden hot spring atmosphere. A skin-beautifying water boasting the most abundant volume in Unzen.

It has a long history as a famous hot spring opened in 1731 (the 16th year of the Kyoho era). It is said that even Shoin Yoshida once visited.

Opened in 1919 (Taisho 8) as a public bathhouse, it is now popular with day-trip visitors as an external bath for Unzen Onsen Seiunso. Hot spring water constantly gushes out behind the building, and the steam enveloping the structure creates an atmosphere like a hidden hot spring. Boasting the highest discharge volume in Unzen Onsen at approximately 440 tons per day, fresh hot spring water is poured directly from the source into the bathtub. The cloudy white water is a simple sulfur spring with a mild acidity of pH 4.3. After bathing, your skin will feel moist and smooth. It is easy to see why hot spring lovers from all over the country visit.

Enjoy the Kojigoku atmosphere in your own home bath.

Unzen Onsen is broadly divided into three hot spring areas: Furuyu, Shinyu, and Kojigoku, with Kojigoku Onsen being particularly known for its intensely cloudy white water. However, the concentration and color of the sulfur spring can vary from day to day, reminding us once again that hot springs are a natural phenomenon.
Bath salts that faithfully reproduce the hot spring's components, color, and scent are also sold so that you can enjoy this milky water at home. They are recommended not only as souvenirs but also for personal use.

This famous hot spring, highly regarded for its medicinal properties and long cherished as a therapeutic bathhouse said to cure all illnesses, heals the hearts and bodies of travelers.

Local
Supporter

The hot water is quite hot, so please be careful when entering. It is said that stirring the water from the bottom of the tub, where the temperature is lower, makes it relatively easier to enter.

Kojigoku Onsen-kan

• 462 Unzen, Obama-cho, Unzen-shi, Nagasaki Prefecture MAP
• Approx. 20-minute walk from KAI Unzen
• 9:30 - 19:00
• Wednesday
• Bathing fee: Adults 500 yen, elementary school students and under 250 yen, 3 years old and under free
• 0957-73-3273 (Unzen Onsen Seiunso)
• Free
• Simple sulfur spring
• Shampoo and other amenities provided

2
Yunosato Onsen Public Bathhouse Dankyu-buro

The oldest public bathhouse in Unzen Onsen, a place of relaxation for the local community.

"Dankyu" means "rakkyo" (scallion) in the Unzen dialect, and the name comes from the fact that large barrels used for pickling scallions were once used as bathtubs. Even though they are no longer barrels, the nickname remains and is still beloved. Due to this history, the current bathtub is also oval-shaped.

The hot spring is a sulfate spring with a high acidity of pH 2.3, but it feels soft on the skin and is said to be effective for chronic neuralgia, muscle pain, and fatigue recovery. The free-flowing hot spring water is poured generously into the deep bathtub, allowing you to fully enjoy the bath as it envelops your entire body up to your neck.

Enjoy the famous hot spring at a leisurely pace, mingling with the local people.

Thanks to the quality of its spring water and its retro atmosphere, it is also popular with tourists. As a public bathhouse, for the locals, it feels almost the same as their own home bath. Many people visit at fixed times every day, such as in the morning before work or at night after finishing work. Follow the lead of the locals and take a casual stroll to the hot spring. It is a nostalgic bathhouse that perfectly suits such a scene.

Since it is open from morning until late at night, you can visit empty-handed whenever the mood strikes. Original towels with a cute checkered pattern are also sold, so be sure to take one home as a souvenir of your hot spring trip after using it.

Local
Supporter

I hear that many homes in Unzen do not have their own bathrooms. Perhaps that is why there is such a homey atmosphere, as if it were an extension of one's own home.

Yunosato Onsen Public Bathhouse Dankyu-buro

• 303-1 Unzen, Obama-cho, Unzen City, Nagasaki Prefecture MAP
• Approx. 5-minute walk from KAI Unzen
• 9:00 - 22:00
• None
• Bathing fee: Adults 200 yen, elementary school students 100 yen
• 080-5286-2576
• Free
• Acidic/Iron (II, III) - Simple hot spring
• No shampoo or other amenities provided

3
Naminoyu Akane

It feels just like floating on the sea! An open-air bath exclusively for private use located on the water.

A private open-air bath facility operated by Hotel Orange Bay. Located in the Obama Onsen district facing Tachibana Bay on the west side of the Shimabara Peninsula, it is the closest facility to the sea, situated right on top of the breakwater blocks. The vast ocean spreads out before your eyes, and at high tide, the difference between the bathtub and the sea surface is only 20 cm. You will feel as if you are floating, becoming one with the sea.

The spring quality is sodium-chloride. Salt springs are said to warm the body thoroughly and have a high heat-retention effect. Since it is exclusively for private use, you can have this superb view and hot spring all to yourself without any hesitation. You can enjoy a blissful moment, soaking in the hot spring at your leisure while admiring the magnificent view and listening to the sound of the waves.

Aim for sunset and bathe while watching the sun sink into Tachibana Bay.

Bathing while watching the sunset over Tachibana Bay is an exceptional luxury. With nothing to obstruct your view and almost no distance from the sea surface, the impact is truly impressive. The sight of the sky turning madder red and the sun sinking below the horizon enhances the hot spring atmosphere.

You can also enjoy bathing at night while gazing at the starry sky. You can enjoy a different atmosphere from the daytime or sunset. Listening to the scent of the sea and the sound of the waves, the ever-changing expressions of the sea and sky will never cease to fascinate visitors.

Local
Supporter

Right nearby is "YUASOBI," a coin-operated private hot spring facility in the same group. It also comes with a steam sauna.

Naminoyu Akane

• 20 Marina, Obama-cho, Unzen City, Nagasaki Prefecture MAP
• Approx. 20 minutes by car from KAI Unzen
• 10:00–23:00 (Last entry 22:00)
  *May be unavailable during bad weather, spring tides, or high tide.
• Irregular holidays
• Bathing fee: 3,000 yen for 50 minutes for 1–4 people; +500 yen per person for 5 or more people.
• 0957-76-0883 (YUASOBI)
• Available
• Sodium-chloride spring
• Reservation required by phone on the day or the day before. Please check in at the private hot spring "YUASOBI" when bathing. Shampoo and other amenities are not provided.

4
Wakihama Onsen Bathhouse (Otasshan-yu)

A traditional public bathhouse that feels as if time has stood still since the early Showa period.

Founded in 1937 (Showa 12), it retains a strong atmosphere of that time. Open from 5:00 AM, it is an indispensable presence for the townspeople, with many regular customers such as fishermen and farmers who start their day early.

Both the men's and women's areas have two bathtubs each. Although the structure is aged, it is a pleasant space that is well-maintained. The time when the morning sun shines into the bathtubs is particularly beautiful, further enhancing the charm. The 'Otasshan-yu' style is for regular customers to set the temperatures of the lukewarm and hot baths themselves every morning. This episode shows just how deeply rooted this hot spring is in the lives of the local people.

A nostalgic atmosphere that evokes a sense of longing for the past.

The atmospheric changing room is also exceptional. The wooden lockers, used since the establishment's founding, tell a long history. There is a bandai (attendant's booth), which is rare nowadays, and the original hot spring efficacy sign from the time of opening on the wall. You can immerse yourself in a nostalgic mood, as if you have traveled back in time to the early Showa period. The owner's desire to preserve the charm of the original establishment while performing repairs is deeply felt.

The water quality is a sodium-chloride spring, just like other hot springs in Obama Onsen. It feels soft on the skin, and after bathing, your body feels warm to the core. It seems to heal your daily fatigue all at once.

Local
Supporter

It is affectionately known by locals as "Otasshan-yu." As a symbol of the local landscape, it has also been certified as one of Nagasaki Prefecture's "Townscape Assets." It is an irreplaceable town treasure that we hope will continue to exist in this place for years to come.

Wakihama Onsen Bathhouse (Otasshan-yu)

• 7 Minamihonmachi, Obama-cho, Unzen-shi, Nagasaki Prefecture MAP
• Approx. 21 minutes by car from KAI Unzen
• Approx. 5-minute walk from the "Minamihonmachi Kominkan-mae" bus stop on the Shimatetsu Bus line
• 5:00–21:00
• None
• Bathing fee: Adults 200 yen, children (6-12 years old) 100 yen, 5 years old and under 50 yen
• 0957-74-3402
• Free
• Sodium-chloride spring
• No shampoo or other amenities provided

5
Hot Foot 105

Relax while looking out at the sea at Japan's longest footbath.

Obama Onsen is said to be closest to the magma chamber of the Unzen volcano located beneath Tachibana Bay, with a source temperature of 105°C. This is Japan's longest footbath, measuring 105 meters in total length, named after the source temperature.

The footbath stretches along Tachibana Bay, offering a luxurious location where you can relax while gazing at the sea. At dusk, the entire area is dyed orange, wrapped in a romantic atmosphere. There is also a walking footbath where pebbles embedded in the bottom stimulate the pressure points on the soles of your feet, and a pet footbath space where you can enjoy the footbath with your dog, making it crowded with many people on holidays.

Be moved by the delicious taste of vegetables steamed with hot spring steam.

A large steaming pot is adjacent to the footbath facility, where you can bring your favorite vegetables and seafood to steam with the hot spring steam. Use of the pot is free, and if you do not have a basket, you can rent one for a fee. Even if you do not bring your own ingredients, you can buy items such as eggs and sweet potatoes at the shop.
Because the source is high-temperature, its power is immense. Eggs take 8 to 10 minutes, and sweet potatoes take about 20 minutes to be thoroughly warmed to the core. You can also enjoy the steamed ingredients while relaxing in the footbath. The umami and sweetness of the ingredients are concentrated, making them exceptionally delicious.

Local
Supporter

Near the footbath, there is a "Yudana" (hot water shelf) where abundant hot spring water exceeding 100°C flows down. The billowing steam is quite impressive.

Hot Foot 105

• 905-70 Kitahonmachi, Obama-cho, Unzen City, Nagasaki Prefecture MAP
• Approx. 20 minutes by car from KAI Unzen
• 10:00-19:00 (Steaming pot until 18:30)
  Nov-Mar 10:00-18:00 (Steaming pot until 17:30)
• 3rd Wednesday, Jan 4, Jan 5, irregular holidays
• Free
• 0957-74-2672 (Obama Onsen Tourist Information Office)
• Paid
• Sodium-chloride spring

6
Footbath Plaza

An oasis in the hot spring town that heals tired feet after a long walk.

A roofed footbath tucked away in the Unzen Onsen town. It features a circular tub about 4 meters in diameter, which can seat around 10 people. If you look at the hot spring source in the center of the tub, you can see the water bubbling up endlessly. The area is wrapped in a gentle scent of sulfur, and just sitting down and soaking your feet will instantly soothe your fatigue. Footbath towels are sold for 100 yen each at the nearby parking lot toll booth, so you can visit empty-handed with peace of mind. Since it is free to use, you can easily drop by when you are tired from touring the hells or strolling through the hot spring town.

Local
Supporter

Some restaurants and inns in the Unzen Onsen town offer footbaths, hand baths, and even finger baths on their premises. Unzen truly lives up to its reputation as a hot spring paradise.

Footbath Plaza

• 320 Unzen, Obama-cho, Unzen City, Nagasaki Prefecture MAP
• Approx. 7-minute walk from KAI Unzen
• 24 hours
• None
• Free
• 0957-73-3434 (Unzen Onsen Tourist Information Office)
• None
• Simple sulfur spring