Japan’s onsen (温泉) hot spring culture is one of the country’s most beloved traditions. From mountain ryokan to seaside resorts and urban bathhouses, soaking in mineral-rich waters is a cornerstone of Japanese wellness and travel. This guide covers everything you need to know to enjoy onsen as a visitor.
What Is an Onsen?
An onsen is a natural hot spring bath fed by geothermal water. To qualify as a genuine onsen under Japanese law, the water must meet specific temperature and mineral content standards. Japan has thousands of certified onsen across the country, fueled by its volcanic geology.
Onsen differ from sentō (public bathhouses), which use heated tap water rather than natural spring water. Both follow similar etiquette but only onsen carry the geological distinction.
Major Onsen Regions
Hakone (Kanagawa Prefecture)
One of Japan’s most accessible onsen destinations from Tokyo (about 90 minutes by Romancecar from Shinjuku). Hakone offers mountain scenery, views of Mt. Fuji on clear days, and numerous ryokan with private and public baths. The area is served by the Hakone Freepass, which covers trains, buses, and the iconic Hakone Ropeway.
Beppu (Oita Prefecture, Kyushu)
Beppu is one of the highest-volume onsen resort cities in Japan. It is famous for the “Jigoku Meguri” (Hell Tour) — eight dramatically coloured natural hot spring pools designed for viewing rather than bathing. Beppu’s waters include mud baths, sand baths, and steam baths in addition to traditional soaking pools.
Kusatsu (Gunma Prefecture)
Kusatsu is consistently ranked among Japan’s top onsen towns. The centrepiece is the yubatake (hot water field) — a large wooden box structure through which the 55°C water flows to cool naturally. Kusatsu’s acidic waters are said to be particularly effective for skin conditions. The area receives heavy snowfall in winter, making it popular for combined ski and onsen trips.
Noboribetsu (Hokkaido)
Hokkaido’s premier onsen resort, set in a volcanic valley called Jigokudani (Hell Valley). The waters here contain nine different types of spring water — unusually diverse even by Japanese standards. Large hotel complexes with elaborate indoor and outdoor baths dominate the area, and snow monkeys are not present here (those are in Jigokudani, Nagano — a different park).
Kinosaki Onsen (Hyogo Prefecture)
A historic onsen town known for its seven public bathhouses (sotoyu) arranged along a willow-lined canal. Guests staying at local ryokan receive a bath-hopping pass and often wander between the bathhouses in yukata robes — the quintessential onsen town experience. Kinosaki is accessible from Osaka in about two hours by limited express train.
Nyūtō Onsen (Akita Prefecture)
A cluster of small, rustic hot spring inns deep in the mountains of Tohoku. The milky white waters are iconic, and the remote forested setting attracts visitors seeking a quieter, more atmospheric onsen experience away from larger resort towns. Best visited in winter when snow blankets the surrounding forest.
Arima Onsen (Hyogo Prefecture)
One of Japan’s oldest onsen resorts, situated in the mountains behind Kobe and easily reached from Osaka or Kyoto. Arima has two types of water: Kinsen (gold spring, iron-rich, rust-coloured) and Ginsen (silver spring, clear carbonated or radium water). The hillside town retains a traditional atmosphere with stone-paved lanes and historic inn buildings.
Types of Onsen Baths
| Type | Description |
|---|---|
| Rotenburo (露天風呂) | Outdoor bath; the most prized type, often with mountain, forest, or ocean views |
| Uchifuro (内風呂) | Indoor bath inside a ryokan or bathhouse |
| Kashikiri / Kazokuburo | Private or family bath for exclusive use; available at many ryokan for a fee |
| Sunayu | Sand bath where attendants bury bathers in geothermally heated sand |
| Doroyu | Mud bath; specialty of certain areas like Beppu |
| Ashiyu (足湯) | Foot bath; free public foot-soaking facilities found throughout onsen towns |
Onsen Etiquette for Visitors
Onsen have specific customs that are important to follow. Most are common sense once you understand the reasoning — keeping the baths clean and maintaining a relaxed atmosphere for everyone.
- Wash before entering: Always use the shower stations (seated wash areas with soap and shampoo) to scrub thoroughly before entering the communal bath.
- No swimwear: Traditional onsen are bathed in the nude. Swimwear is explicitly banned at most public facilities as it can contaminate the water with detergent and fabric.
- Towel placement: Bring a small towel but keep it out of the water. Many bathers fold it on their head; set it aside on the bath edge if you prefer.
- No splashing or swimming: Onsen are for quiet soaking, not exercise.
- Long hair tied up: Keep hair tied or use a shower cap to prevent it entering the water.
- No alcohol before bathing: The heat can intensify the effects of alcohol and cause dizziness or fainting.
- Separate facilities by gender: Most traditional onsen separate baths by biological sex. Konyoku (mixed bathing) onsen exist but are increasingly rare.
- Hydrate: Drink water before and after soaking; dehydration is a real concern, especially in hotter spring types.
Tattoo Policies
Many onsen — particularly those attached to large resorts and chain establishments — maintain blanket no-tattoo policies. This is a long-standing practice rooted in historical associations between tattoos and organised crime, though enforcement and attitudes vary significantly.
Options for tattooed visitors include:
- Book a private bath: Kashikiri facilities are available at most ryokan and some public bathhouses for an additional fee — typically ¥500–¥3,000 per session.
- Seek tattoo-friendly facilities: A growing number of onsen explicitly welcome guests with tattoos. Search in Japanese for “タトゥーOK 温泉” or check specialist travel guides.
- Day spas and sento: Some urban sentō and spa facilities have updated their policies and welcome tattooed guests.
Onsen for Foreign Visitors: Practical Tips
- Ryokan packages: The classic way to experience onsen is as part of a ryokan stay (traditional Japanese inn). Most ryokan include dinner and breakfast and provide yukata robes for use on-site and around the onsen town.
- Day-trip bathing (higaeri nyūyoku): Many onsen facilities allow day visitors to use the baths without staying overnight, typically for a fee of ¥500–¥2,000.
- Onsen towns with ashiyu: If you’re uncertain about committing to a full bath, start with the free foot baths (ashiyu) found in most onsen towns.
- Seasonal timing: Rotenburo (outdoor baths) are most atmospheric in winter — soaking in steaming water while surrounded by snow is a classic experience. Summer mountain and coastal onsen have their own appeal.
- Water temperature: Japanese onsen tend to run hot — typically 40–44°C. If you are not accustomed to high temperatures, start with cooler baths and limit sessions to 10–15 minutes at first.
Jigokudani Monkey Park (Nagano)
Japan’s most photographed onsen scene involves Japanese macaques (snow monkeys) bathing in an outdoor hot spring pool at Jigokudani Monkey Park in Nagano Prefecture. The monkeys bathe voluntarily throughout winter and are habituated to human visitors. Access is via a 30-minute walk from Kanbayashi Onsen — no facilities to enter, just an open outdoor viewing area. Nearby Shibu Onsen and Yudanaka Onsen offer human bathing facilities and accommodation.
Sample Onsen Itinerary: Tokyo Base
- Day trip: Hakone (90 min from Shinjuku) — take the Romancecar, use Hakone Freepass, soak at a day-bath facility with Mt. Fuji views if clear
- Overnight: Nikko or Kinugawa Onsen (Tochigi, ~2 hours from Tokyo) — forested mountain setting, less crowded than Hakone
- Weekend: Kusatsu Onsen (Gunma, ~4 hours by bus) — stay in the town centre, use the public Sainokawara rotenburo, watch the yubatake at night
Related Pages
For more on planning your trip, see our First-Time Japan Guide and Best Time to Visit Japan. If you are considering a ryokan as part of your accommodation mix, see Where to Stay in Tokyo or Where to Stay in Kyoto.