Misasa Onsen is a hot spring resort in Misasa Town, Tohaku District, Tottori Prefecture, stretching along the Mitoku River and known as a famous spa with one of the world’s highest concentrations of radon-bearing radioactive springs. It preserves the atmosphere of an old therapeutic bath town, with inns, public baths, and footbaths lining the river. In particular, the open-air Kawara-buro that rises from the riverbank of the Mitoku River, and the National Treasure Nageiredo of Sanbutsu-ji Temple on the sheer cliffs of Mt. Mitoku, are signature sights of Misasa.

In short, what defines Misasa Onsen is not flashy appearance or smell, but the amount of radon and radium dissolved in the water. The springs are often colorless, clear, and nearly odorless, making this a hot spring area that is hard to judge by feel alone and is often best understood through its analysis report. This article organizes Misasa Onsen’s characteristics and water quality, highlights such as Kabu-yu and Kawara-buro, the drinking-spring culture, Mt. Mitoku Nageiredo, and access, based on official information from the local tourism association and Misasa Town. Note that the health benefits often associated with radioactive springs, such as hormesis, are not scientifically established, so this article does not make any definitive claims.

This article provides general information and does not guarantee any specific therapeutic or health effects. Scientific views on the health impact of radioactive springs are not settled, and debate continues. Conditions of use, fees, schedules, and operating details for Kawara-buro, Nageiredo visits, and other facilities can change, so be sure to check official information before visiting. If you have a chronic condition, are pregnant, or are feeling unwell, do not overdo it and follow the guidance of your doctor and the facility.

What Is Misasa Onsen? A Therapeutic Bath Town Along the Mitoku River

Misasa Onsen is in Misasa Town, south of Kurayoshi City in central Tottori Prefecture. A hot spring district has formed along the Mitoku River, and the landscape is defined by bridges over the river, the riverbank, and bathing with the river breeze. It retains the culture of traditional therapeutic bathing and has a calmer atmosphere distinct from large, heavily commercialized hot spring resorts.

As for the origin of the name “Misasa,” one common explanation is the legend that “if you spend three mornings there (stay three nights), you will feel better,” but this remains one of several folklore-based theories and should not be treated as established fact. The place name is read as “Misasa,” and first-time visitors should note that it is easy to misread.

The hot spring district is compact, and one of the pleasures of Misasa is walking along the river to visit public baths, footbaths, and drinking springs. Its reputation as a famous hot spring is strong, and it is often counted among Japan’s most distinctive famous hot springs. For its place among other renowned hot springs, see 10 Famous Hot Springs in Japan.

Its Defining Feature: One of the World’s Leading Radium Springs

The biggest feature of Misasa Onsen is that it is a high-concentration radium spring (radioactive spring) said to be among the world’s best known. A radioactive spring is one whose water contains a certain amount or more of radioactive substances such as radon, and it is also called a radon spring or radium spring. Here, radioactivity refers to naturally occurring, very small amounts of radiation derived from rocks underground, which is different in nature from artificial radioactivity.

According to the Ministry of the Environment’s Guidelines for Mineral Spring Analysis, a radioactive spring is one containing at least 8.25 Mache units of radon, or about 111 Bq/kg. Misasa is known for springs that greatly exceed this standard, and its sources have long been studied for their radon content. Because radon has a short half-life and escapes into the air easily, radioactive springs are stronger when they are closer to the source and when the water has just been drawn.

What should be noted here is the idea of hormesis, the notion that trace radiation from radon or radium is beneficial to health. It is sometimes presented in hot spring brochures as if it were an effect, but this is not a scientifically established fact, and debate continues, including critical views. It is best not to interpret Misasa’s waters as definitively “effective for cancer” or “boosting immunity.” For standards and safety perspectives on radioactive springs themselves, see Radioactive Spring (Radon Spring) Standards and Safety. For a broader view of spring types, see Hot Spring Water Types Guide.

Highlights: Kabu-yu, Kawara-buro, and More

The pleasure of Misasa is visiting the public baths and open-air baths scattered along the river. Among them, the “Kabu-yu,” said to be the original source bath, and the “Kawara-buro,” which rises on the riverbank of the Mitoku River, are essential to any discussion of Misasa. Because hours, fees, mixed-bathing rules, and facilities can change, check official information before you go.

Kabu-yu is a long-standing bath traditionally regarded as the original spring and a public bath loved by local residents. Kawara-buro is an open-air bath in a highly exposed location on the riverbank of the Mitoku River, visible even from the bridge. While it is famous as a local specialty, its openness means that usable hours, mixed-bathing rules, and whether women can easily bathe there vary by facility and season, so advance confirmation is essential. The appeal of enjoying an open-air bath in harmony with the scenery is part of what makes Misasa unique.

Misasa’s Drinking-Spring Culture

Misasa Onsen has a culture of drinking the hot spring water. As with any hot spring area, drinking is only allowed in places where it is expressly permitted, and not every spring can be consumed. Rather than casually drinking spring water as part of sightseeing, you must always follow the instructions at the drinking-spring area.

Guidance on drinking radioactive spring water and inhaling gas is provided by each facility, including suggested amounts and methods. Because there are also recommended limits for quantity and frequency, and it may not suit everyone depending on health or medical history, it is not appropriate to drink large amounts on your own judgment. For the background and precautions of this practice, see The Culture of Drinking Hot Spring Water.

Nageiredo of Sanbutsu-ji Temple on Mt. Mitoku

If you visit Misasa, one place worth extending your trip for is Mt. Mitoku Sanbutsu-ji Temple. Its inner sanctuary, Nageiredo, is a National Treasure building set into a notch in a vertical cliff and is known as a sacred site of Shugendo. How it was built in such a place remains mysterious, and one legend says it was thrown into place by the founder’s spiritual power, which is why it is called Nageiredo.

The pilgrimage hike to worship it up close is a rugged ascent with chain sections, steep slopes, and sections where you must grip tree roots to climb. Because there is a risk of slipping and falling, conditions such as proper footwear, entering in groups of two or more, and confirming reception procedures and clothing are in place. Entry may also be restricted depending on weather or season. This is not a place to climb casually in light clothes, so if you are considering the hike, be sure to confirm gear, reception conditions, and whether entry is permitted using official information.

A viewing spot for distant worship has also been set up at the foot of the mountain, so if hiking is difficult, you can still admire the National Treasure from there.

Access and How to Plan Your Stay

The usual way to reach Misasa Onsen is by combining train and bus. The rail gateway is JR Kurayoshi Station on the Sanin Main Line, and the bus ride from Kurayoshi Station to Misasa Onsen is about 20 minutes. Limited express trains stop at Kurayoshi Station, making it accessible from the Kansai and Okayama areas. By air, Tottori Sand Dunes Conan Airport and Yonago Kitaro Airport are used. Timetables, travel times, and last services can change, so be sure to check the official schedule before you go.

If you are only strolling around the hot spring town and visiting public baths and drinking springs, even a short stay can be enjoyable. But if you also plan the pilgrimage hike to Nageiredo, you should allow at least half a day. Because the hike requires time and physical effort, staying one night makes it easier to enjoy both the onsen and the mountain visit without rushing. If you want to find inns or day-use bathing facilities in Misasa, use the Facility List, which lets you filter by area and budget.

FAQ

Is the radium spring at Misasa Onsen harmful to the body?

The natural radiation in Misasa’s water comes from rocks underground, and the amount received during normal bathing is considered very small, so there is no need to be overly afraid. On the other hand, it cannot be said to be completely harmless, so it is best to avoid long baths and enjoy it in a well-ventilated setting. If you are pregnant, have a chronic condition, or feel anxious about it, follow the guidance of the facility.

Does the hormesis effect of radium springs really exist?

The hormesis theory, which suggests that trace radiation may be beneficial to health, is an interesting hypothesis, but it has not been scientifically established, and debate continues, including critical views. It is better not to treat Misasa’s waters as having a proven effect, and instead enjoy the scenery and culture of the hot spring town.

Can anyone use Kawara-buro?

Kawara-buro is an open-air bath on the riverbank of the Mitoku River and is known as a Misasa specialty. However, because it is very open, usable hours and mixed-bathing rules vary by facility and season. If you are considering bathing there, we recommend checking the usage conditions in advance through official information.

Is Nageiredo on Mt. Mitoku easy to climb?

No, it is not an easy place to climb. The pilgrimage hike to Nageiredo is a rugged route with chain sections and steep slopes, and there is a risk of slipping and falling. Conditions include proper gear, confirmation of reception procedures and clothing, and entering with at least two people, and entry may be restricted depending on weather. Always check the official guidance for conditions and whether entry is allowed.

How do I get to Misasa Onsen?

The usual route is a train-and-bus combination. JR Kurayoshi Station is the gateway, and the bus ride from Kurayoshi Station to Misasa Onsen is about 20 minutes. By air, Tottori Sand Dunes Conan Airport and Yonago Kitaro Airport can be used. Schedules and travel times change easily, so check the official timetable before your visit.

Summary

Misasa Onsen is a famous hot spring area along the Mitoku River in Misasa Town, Tottori Prefecture, known as one of the world’s leading high-concentration radium springs. It has a distinctive blend of hot springs, faith, and nature, with Kabu-yu said to be the original spring, Kawara-buro rising from the riverbank, a drinking-spring culture, and the National Treasure Nageiredo standing on a cliff. The water itself is nearly colorless, clear, and odorless, and its quality is the kind best understood through an analysis report that shows radon and radium content.

For travelers, the practical approach is to avoid making definitive claims about often-mentioned health effects such as hormesis, since they are not scientifically established, and to enjoy the area calmly without being overly fearful. Because the conditions for using Kawara-buro, whether drinking spring water is allowed, the gear and reception requirements for the Nageiredo hike, and bus schedules can all change, it is best to confirm everything in advance through official information. For the overall picture of spring types, see Hot Spring Water Types Guide.

Sources

• Misasa Onsen Tourism Association
• Misasa Town
• Ministry of the Environment, "Guidelines for Mineral Spring Analysis (Revised in 2014)"
• Ministry of the Environment, "Protection and Use of Hot Springs"