Outdoor Onsen (Rotenburo): Where to Find Open-Air Baths

There are plenty of big reasons to visit Japan, but for me, soaking in an outdoor onsen is one of the small joys that makes every trip feel special. Locals call them rotenburo, and they’re all about slowing down.

In this guide, I’ll show you how to enjoy outdoor onsen in Japan and where to find the best ones.

What is an outdoor onsen (rotenburo)?

If you’ve ever dreamed of soaking in a steaming hot spring baths while looking out at mountains or a river, you’re already imagining an outdoor onsen. 

In Japan, these are called rotenburo, and they’re one of the best ways to experience hot springs. 

Unlike indoor baths, you get fresh air, wide-open views, and the feeling that you’re part of the landscape. 

I always think rotenburo are at their best in winter, when snow is falling all around, or in autumn, when the leaves turn brilliant red. Once you try an outdoor onsen, you’ll never forget it.

Types of outdoor onsen you’ll see

I’ve learned that not all outdoor onsen are created equal. 

Some are simple public open-air baths where locals go for a quick soak after work. They feel authentic and unpretentious. 

Others are attached to onsen ryokan with outdoor rotenburo, where you step outside in your yukata and sink into steaming spring water under the stars. 

If you like privacy, you can book a private outdoor onsen room. It’s perfect if you want the experience all to yourself or if you have tattoos and don’t want to worry about rules. 

Then there are the dramatic ones: baths carved beside rivers, on cliffs, or overlooking the sea.

How to use Japan outdoor onsen

If you’re new to open-air hot springs, don’t worry. Just follow these steps and you’ll fit right in:

1. Wash first: Always shower before you soak. Cleanliness comes first in Japanese hot spring etiquette.
2. Bring a small towel:  I carry a small one, but it never touches the water. The trick is to balance it on your head while you relax.
3. Step in slowly: The water is hot, so let your body adjust. Take your time and enjoy the moment.
4. Stay quiet and relaxed: Onsen are all about peace. Keep voices low, avoid splashing, and soak in the view.
5. No swimwear: Unless the sign says otherwise, you bathe nude. That’s the norm.
6. Check tattoo rules: If a place doesn’t allow tattoos, I go for a private open-air bath at a ryokan. Problem solved.
7. Don’t overdo it: Ten to fifteen minutes is plenty. Step out, rest, and sip some water if you need to cool down.

Where to find outdoor onsen in Japan

You can find rotenburo everywhere, but some regions are more famous than others. To make planning easier, I’ve grouped the best outdoor onsen in Japan from north to south.

Northern Japan: Hokkaidō and Tōhoku

Dreaming of a snow onsen? this is where to go. The rotenburo here feel wild and natural, especially in winter when the steam rises against the cold air.

• Asahidake Onsen (Hokkaidō): After a hike, sliding into these mountain pools feels like the best reward.
• Sukayu Onsen (Aomori): Known for its huge “Bath of a Thousand Bathers,” it’s even more impressive with snow falling around you.
• Nyūtō Onsen (Akita): A group of rustic open-air hot springs deep in the mountains.
• Ginzan Onsen (Yamagata): You can soak outside. Then wander through a town lit with lanterns that feels like it belongs in a storybook.

Central Japan: Kanto, Kansai, and the Japanese Alps

If you’re staying near Tokyo, Kyoto, or Osaka, you don’t have to go far to enjoy some incredible rotenburo. These hot spring spots are easy to reach and full of charm.

• Hakone Onsen (near Tokyo): Perfect for a day trip, with rotenburo that look out over rolling hills.
• Kusatsu Onsen (Gunma): Famous for its mineral-rich spring waters. Locals say the baths here are some of the healthiest in Japan, and the town itself feels like a classic onsen resort.
• Okuhida Onsen (Japanese Alps): Dozens of open-air baths scattered across the valley with dramatic mountain backdrops.
• Kinosaki Onsen (Hyōgo): Famous for its seven public bathhouses, many with beautiful rotenburo. It’s one of the most friendly onsen towns for visitors.
• Arima Onsen (Hyōgo): One of Japan’s oldest hot spring resorts, known for rare golden and silver waters. Many bathing facilities here also have outdoor baths where you can relax in style.

Southern Japan: Kyushu

Kyushu is known for its welcoming onsen towns, and many inns here feature private rotenburo baths.

• Kurokawa Onsen (Kumamoto): Small ryokan baths hidden among forests, perfect if you want peace and quiet.
• Beppu Onsen (Ōita): A hot spring hub where you can try all kinds of baths, including outdoor pools with ocean views.

From snow onsen in the north to private rotenburo in the south, there’s an outdoor onsen for every traveler.

Seasonal tips for Japan outdoor hotspring

Seasons completely change the vibe of an outdoor onsen. 

In winter, sitting in hot water while snow falls all around you feels unreal. I usually don’t soak too long because the air is so cold, but those few minutes are unforgettable.

In autumn, the outdoor baths are surrounded by deep crimson and golden leaves, and the scenery is just breathtaking. I always try to time a trip to Japan in early November for that reason.

Spring brings cherry blossoms and fresh greenery. Imagine petals drifting into the water while you soak! It’s so dreamy. 

Summer can be hot and humid, so I like going early in the morning or later at night when the air is cooler.

Booking tips: day-use vs ryokan stays

When it comes to outdoor onsen, you’ve got two main options: day-use or staying overnight at a ryokan.

If you’re short on time, I’d say try a day-use outdoor onsen (higaeri onsen). Many hot spring towns let you pop in for a soak, usually for a small fee, and it’s a fun way to sample different baths in one day. 

I’ve done this in Beppu and loved hopping between rotenburo with different views.

But if you want the full experience, nothing beats an onsen ryokan stay with private open-air baths. You get your own yukata, amazing kaiseki meals, and sometimes even a rotenburo attached to your room. 

I always check the room descriptions when booking. If it says “open-air bath” or “private rotenburo,” you’re in for a treat.

Outdoor Onsen Packing checklist

Here’s what I always bring to outdoor onsen:

• Warm hat or wrap (winter): Helps you stay cozy in a snow onsen.
• Small towel: For modesty and to dry off quickly (keep it out of the bath).
• Large towel: Handy if you’re staying overnight at a ryokan.
• Hair tie or clip: If your hair is long, you’ll need to keep it out of the water.
• Water bottle: Staying hydrated matters more than you think.
• Plastic bag: Perfect for storing a damp towel if you’re doing day-use.

FAQs about Japan outdoor onsen

Before you go

Before you dip into an open-air onsen, it helps to know a little more about Japan’s hot spring culture. I always suggest starting with my guide to the Types of onsen baths so you can see how rotenburo compare with other styles.

If you’re booking a stay, you might be wondering how much time is enough. My post on How long to stay in a ryokan will help you decide whether one night does the trick or if you’d enjoy a slower escape.

Curious about the health side of things? Check out Onsen benefits to learn why these baths leave you feeling so refreshed.

And if you’re not sure what to wear once you’re at a ryokan, my guide on What to wear at a ryokan will make you feel prepared from the moment you arrive.