Useful Information

Japan's Best Wild Onsen: Taking the Extreme Onsen Challenge

Japan's Best Wild Onsen: Taking the Extreme Onsen Challenge

The Extreme Onsen: Nakanosawa-numajiri Onsen

The greatest wild onsen in Japan? Maybe the world?  This massive onsen river in the mountains is the largest of its kind in the entire country! With the help of a professional guide, visitors can traverse unique volcanic terrain to reach this extreme onsen river in the mountains. Bathing in the water here is thought to have many health benefits, as well.

If you are interested in doing this hike, tours can be booked through our tours page.

Poisonous Volcanic Gases and Safety (IMPORTANT!)

First of all: SAFETY. 

Completing this hike is approximately a two hour round trip. It has several stretches of difficult and potentially dangerous terrain. The main danger is that, since Mt. Adatara is a volcano, it is constantly releasing poisonous gases. These sometimes accumulate to dangerous and deadly levels that can cause fainting and even death. Fortunately, the professional guides are available and trained with the tools necessary to safely guide you on your journey.

The approach

The hike is beautiful, with views of a massive waterfall and the surrounding mountains.

Tunnels of trees reminded me of the entryway to a mysterious world. As you get higher, the trail slopes downwards on either side, revealing panoramic views of the surrounding area. Suddenly, you can see the terrain has changed up ahead from green forest to volcanic stones of white and red. This was once the site of a violent volcanic eruption, and the thought of that feels outlandish as the mountain is peacefully quiet. 

Descending into the volcanic valley

The trail drops steeply into the valley, where shadows preserve small pockets of winter snow well into the spring months, something that is important to consider if you are visiting in spring. (Vising in winter would be extremely dangerous and is prohibited.) 

As you continue, the trail can be difficult to identify due to plant overgrowth, the remote nature of this trail and onsen can make it difficult to keep the path clear. When I visited, I was grateful for my guide who kindly helped me cross the large pockets of snow and ice as well as the sections where bamboo shoots had encroached on the trail, making it difficult to pass.

As you descend deeper into the valley, you can appreciate the way the valley forms a bowl of reddish volcanic stone and soil. Unfortunately, this unique shape is what can contribute to the accumulation of fatal levels of poisonous gas! Our guide tested the air and conditions, and determined that we were safe to explore. 

A river of warmth

The blue river of onsen water contrasted sharply with the warm tones of the volcanic landscape; it felt like we had discovered water on Mars. It was amazing how warm the water stayed despite being so exposed to the cool spring air. Wooden channels split off from the river - this onsen water flows through these to underground pipes and fills the baths at eleven different onsen hotels nearby, where it can be enjoyed by guests who want to experience the health benefits without the need to go hiking.  

Bathing

Bathing in the onsen water is thought to have medicinal benefits. The water has a pH of 2.1 that is comparable to lemons! It is unique in Japan as the largest amount of hot spring water to come from one source, the “Numajiri Motoyu”. So if you choose to visit, I hope you will bathe in the water here and experience the refreshing effects of this onsen! 

Disclaimer:

We cannot provide the exact trail information for this hike due to the dangerous nature of poisonous volcanic gases in the area, which have been fatal to some hikers. You may find information about the trail online, likely referencing a different version of the trail that is illegal, and crosses over protected land. In order to experience this beautiful and unique environment in a safe and respectful way, we encourage visitors to hire guides or visit as a part of tours that include guides. Unfortunately, some have chosen not to hire a guide, resulting in a number of casualties on the mountain. Please help us to avoid further tragedies and do not attempt this hike without an experienced guide or encourage others to do so. Thank you for your cooperation.

Taxi Service

There are reservable taxis available to take you from Fukushima Station to the meeting point at 'cafe&activity nowhere'. The price is 33,100 yen (overall) for trips of 1-3 people, and 49,900 yen for a larger taxi carrying 4-8 people. Taxis will be dispatched one hour prior to the start of the tour, and will pick you up from the cafe after the hike is complete. Please be aware that reserved taxis do not depart from the regular taxi rank but slightly to the right (when facing the taxi rank) at a specific pick-up spot for guests with reservations.

Ready to take the plunge? The Extreme Onsen experience is available here! 

 

 

Latest posts

  1. Destination Spotlight

    Among a Sea of Clouds – Climbing Mt. Issaikyo

    Learn more about Mt. Issaikyo on our dedicated webpage. Despite Japan being such a mountainous country, and having lived here for several years, I was surprised to realise I’d never climbed to the summit of a Japanese mountain before. But that all changed recently when I attempted – and defeated, just about – the rugged trip up Mt. Issaikyo, one of Fukushima’s most popular hikes.Here's all the information about not only my trip, but how you can take on this challenge as well.Base Camp: JododairaOverlooking the Jododaira Plateau, the summit of Mt. Issaikyo (1,949m) is one of several possible trips from the Jododaira Visitor Center to different areas of the surrounding Azuma-Bandai mountain range.Many visitors head for the Kamanuma pond to the west or Okenuma pond to the south, both of which offer spectacular views over the water and are particularly stunning when the leaves change colours in autumn. Both of these trips, as well as the climb up to the nearby Mt. Azuma-Kofuji crater, are shorter and less intensive walks accessible to any experience level.The nearby Visitor Center is also a great spot to enjoy lunch; there is a traditional shokudo (canteen) style restaurant that serves classic Japanese staples like curry and ramen. There’s also a souvenir shop, a great place to pick up snacks or Fukushima goods like the iconic akabeko red cow.The Jododaira area in general is well known as being a volcanic one – a major eruption from Mt. Azuma-Kofuji in 1888 created hundreds of lakes, including the popular Goshiki-numa, and the hot mountain spring water serves nearby onsen hotels to this day. Sometimes you’ll see local construction staff wearing gas masks to protect against volcanic gases when exposed for long working days.The Climb: Leg DayAs a first-time hiker, I was a little apprehensive about the journey to the summit, but the initial stretch of the journey was easy – a leisurely walk along the boardwalk through the marshlands heading into the foothills.From there, the path begins to become rockier, steeper and less steady, and this largely continued for the remainder of the hike. There are plenty of natural rest stops on the way, however, including a mountain hut with toilets and medical supplies in case of an emergency.Also, this route provides fantastic views over Azuma-Kofuji. Although it was easy to feel some jealousy towards the visitors who chose the easier hike (only 10 minutes up the steps from Jododaira, then a 45 minute stroll around the crater), the gorgeous weather made for some beautiful photos.Although the volcanic crater is visible further up Mt. Issaikyo, on occasion it was obscured by the rocky slope or by the shifting cloud cover, so the best photo spot was probably somewhere halfway up the ascent.This was also where we met many hikers coming back down the mountain in the opposite direction, many of whom greeted us warmly and wished us luck on our climb.The SummitBy the time we made it to the top, our tired legs and lungs certainly needed a rest, but we were rewarded with breathtaking views of pristine white clouds stretching as far as the eye could see. In contrast to the view from Azuma-Kofuji, which looks across the green expanse of Fukushima City, being surrounded by clouds made it feel like we’d stepped into another world.From here, we wandered slightly to the western part of the summit, where from over a gravelly slope we spied the view that attracts intrepid hikers from all over Japan.Known as Majo-no-Hitomi or ‘The Witch’s Eye’, this flawless lake of crystal blue is truly a sight to behold, and definitely made the tough climb worthwhile.The Descent... in the Wrong DirectionTempted for a closer look, we headed down the steep slopes that lead off the summit. The grip underfoot here can be rocky and unsteady, so this was where my hiking boots came most in handy. Once we got into the more forested areas again, the path occasionally fell away into a slight drop, too, so some very light mountaineering was required.The journey from the summit down to the Witch’s Eye took about thirty minutes, and again we were awestruck:The beauty of the lakefront was even more striking up close, making it the perfect place to stop and recharge our batteries with a quick lunch by the water. We spent another half an hour down here, taking a much-needed rest and enjoying the perfect summer weather.All that was left was to climb Mt. Issaikyo for the second time on the day, and we would be on our way home...By the time we made it back to Jododaira, the fine weather from earlier has dissipated and a deep fog had settled in.The round trip from Jododaira to the summit of Mt. Issaikyo, down to the Witch’s Eye, and back again, took us roughly five and a half hours (stopping for 30mins for lunch), and saw us walk the equivalent of 7.4km.Looking to climb Mt. Issaikyo for yourself? Some important advice: Wear sunscreen! Despite the shaded areas, large parts of the hike are exposed to the elements. Bring plenty of water, and snacks or lunch to keep your energy up! Hiking boots are highly recommended. The mountain is closed to climbers in winter.Looking for more hikes in Fukushima? Consider Mt. Adatara or Mt. Bandai.

    Among a Sea of Clouds – Climbing Mt. Issaikyo
  2. Useful Information

    How to Enjoy Fruit Picking in Fukushima: The Ultimate Guide

    Fukushima Prefecture has been called the ‘Fruit Kingdom’ for its abundance of orchards – in particular, the western half of Fukushima City is overloaded with fruit farms of all kinds and colours. This long strip of farmland is known as the ‘Fruit Line’, with over 20 orchards located in this region alone, and is one of the best places in Japan to enjoy a leisurely fruit picking experience during your trip.Unlike fruit picking in western countries, which is often an all-you-can-pick experience, fruit picking in Japan more closely resembles all-you-can-eat. You are usually given a set time period after you arrive – likely 30 minutes to an hour – during which you’re welcome to pick and eat as much fruit as you like. You’re asked not to take any fruit home with you from the picking area, although most orchards have a shop where the best of recent batches can be bought, often at a lower price than supermarkets.Choose Your SeasonOne of the unique features of an area with so many orchards – and a variable four-season climate like Fukushima’s – is that there’s something delicious in season almost the whole year round. Since Fukushima is Japan’s second-largest exporter of peaches, they are one of the prefecture’s biggest symbols, and you’ll see them on billboards and posters wherever you go. That makes peach-picking season – roughly mid-July through September – one of the most popular times to visit the Fruit Line, and the peaches are first-rate no matter which orchard you visit.Also extremely popular is strawberry picking, available from November all the way through to May, and apple picking is also a big hit between August and December. These are the main exports of the famous Fruit Line, but depending on the season you can visit and taste everything from cherries and blueberries in summer to grapes and Japanese pears (nashi) in autumn.What to ExpectThe procedure is slightly different for each orchard – some stores have a ticket vending machine, others you pay at the front counter – but on the whole, orchard staff are very familiar with overseas visitors and will be happy to help you. During the fruit picking experience, a member of the fruit picking staff will explain how to recognise the difference between ripe fruit and non-ripe, and many orchards also have fruit on nearby tables that has been recently picked and is also free for you to eat. Depending on the fruit you’re picking, you may also be given a bucket (for example, for peach skins or pits) and a small knife to cut fruit or peel skin (although fruits like peaches and apples are arguably sweeter with the skin still on). Although English explanations are rarer, it’s relatively easy to understand the staff via gestures and demonstrations.After your time is up, retire to the main shop of the orchard to browse the local products – juices and jams are especially popular and make for good gifts. Marusei Orchard in particular boasts an onsite café that uses their own produce in a variety of sweet treats and parfaits, and there are pictures to help you decide.Getting to the Fruit LineSince buses are available but infrequent, and the Fruit Line is littered with orchards run by different families and companies, using a car or bicycle offers more freedom to explore the area and enjoy the local scenery. Here are our recommendations for getting to the Fruit Kingdom for yourself...Car RentalRenting a car in Japan is an excellent way to get around, and the sign-up process is surprisingly easy. In Fukushima City there are three rental stores close to the west exit of the bullet train station: the JR rental store located near the west exit bus stops; the Toyota store opposite the west exit courtyard; and the Orix store one block further west. All three offer single-day rentals (small ‘kei’ cars have four seats and are the most affordable option) and can be booked online with English support.On the day of the rental, go to the store and state your name. After checking your paperwork and ID, the store staff will ask you to inspect the car for damage, and mark any scratches or dents on their inspection sheet so you’re not charged when returning the vehicle. If required, the staff can also change the car’s navigation system to English.In order to drive in Japan, visitors must obtain an International Driver’s Permit and keep it on their person at all times while driving. You also must show the permit to staff during the rental process.JR Rent-a-car / Toyota / OrixBicycle RentalExploring the countryside on a rental bicycle is one of the best ways to experience Japan – when the weather is nice – and it’s a great way to ‘hop’ multiple orchards if you’re looking to peruse the local products. Despite being ringed to the west by the Azuma mountain range, the Fruit Line is largely flat with a splendid green atmosphere, with most roads being flanked by fruit trees.As an example, if going to Marusei Orchard, take the Izaka Line to its final station of Iizaka-onsen (approx. 20mins), and rent cycles at the station. From there, take a leisurely bike ride headed west for about 10-15 minutes until you arrive at the orchard. (This itinerary would also work for visiting any orchard on the Fruit Line by bicycle.)TaxiTaxis are plentiful and available from the west exit of Fukushima Station, with drivers very familiar with the layout of the Fruit Line and able to drop you at any orchard of your choice. If returning to Fukushima Station, the orchard staff would be able to call a taxi to pick you up. However, since a round trip to the west of the city would likely cost around 7,000 yen – roughly the same price of a rental car for the day – it may be worth considering driving yourself or taking a train and renting bicycles.To learn more about the Fruit Kingdom and book your spot, visit our reservation page.

    How to Enjoy Fruit Picking in Fukushima: The Ultimate Guide
  3. Destination Spotlight

    The Tourism of Hope: A Guide to the Key Sites of Fukushima’s Post-Disaster Revitalization

    The Great East Japan Earthquake of March 11, 2011 devastated huge swathes of the Tohoku region; in Fukushima Prefecture alone, over 4,000 people lost their lives as a result of the disaster. Known by many locals as the triple disaster – earthquake, tsunami, and nuclear power plant failure – the events of 2011 stand as one of the most severe disasters in modern history.Over ten years on, Fukushima is once again a bustling tourist destination.Although citizens of coastal areas were ordered to evacuate in the immediate aftermath of the disaster, extensive revitalization efforts have allowed people to come back, and these days the ‘difficult-to-return’ zone covers just 2.9% of Fukushima Prefecture. Radiation levels are roughly the same as other world cities; you can learn more about safety in Fukushima here.If you’re looking to learn first-hand about the disaster, here are some of the must-see locations on Fukushima’s eastern coast.The Great East Japan Earthquake and Nuclear Disaster Memorial MuseumThis museum, known to locals as Denshokan, accounts in great detail not only the events of the disaster, but the extensive efforts of local authorities to restore the region to its lively former self. This beautiful modern complex, completed in 2020, asks visitors to consider both of the destructive power of natural disasters, and the important lessons we can learn about disaster preparedness for future generations. Four times a day, local residents share their experiences of the events of March 2011 and answer questions from museum guests. Their testimony is both insightful and very moving, and for many travellers remains their most lasting memory of their visit.The museum is a mixture of written records and audiovisual materials, documenting the immediate response from local and national government, and features many interactive exhibits encouraging guests – especially students – to consider how a region should attempt to recover after a tragedy of this scale. Particularly charming are letters of support the people of Fukushima received from children worldwide in the wake of the disaster.Adults enter for 600 yen; high school students or younger for 300 yen. To learn more about Denshokan and how to experience this beautiful modern museum for yourself, visit our dedicated web page.Futaba Town Art DistrictThis seaside town was once home to roughly 7,000 people – currently the population is around one hundred people or less. Many of those who once lived in the disaster-affected area have made new lives for themselves elsewhere, but the people and the spirit of Futaba has been commemorated in the form of gigantic murals around the town. As you walk from mural to mural, it’s hard not to think of the lively townscape it must have been before the disaster struck over ten years ago.Aside from the memorial museum, which is based in Futaba, you can also visit the Asano-Nenshi office, known to many as the ‘Super Zero’ towel factory. Established by an Asano-Nenshi executive who lived in Fukushima as a university student, the factory is perhaps the biggest and most significant visual indicator of a little town looking towards the future.Read more about Futaba Town’s stunning art district.Ukedo Elementary SchoolLocated in nearby Namie Town, Ukedo Elementary School is one of the most striking leftovers from the 2011 disaster. Built close enough to see the ocean, the school was ravaged by the tsunami 40 minutes after the initial quake – that no one in the school lost their lives has been hailed as a miracle. The school grounds, left largely untouched, are now a museum commemorating the remarkable story of how the Ukedo students and teachers safely evacuated on that fateful day in March 2011.Visitors can wander the wreckage of former classrooms and witness the water damage on the walls and floors. Perhaps most awe-inspiring is the sight of the gymnasium, its floor punctured and warped by the immense pressure of the tsunami water.The upper floor of the building features some classrooms as they were before the disaster, and includes memorabilia and wreckage found by revitalization workers. A QR code at the entrance also provides support for other languages including English.Entrance to the school costs 300 yen for adults, 200 yen for high school students, and 100 yen for elementary and middle school students. The building is closed on Tuesdays.For more details about Ukedo Elementary School and other places to visit in Fukushima’s coastal region, see the Fukushima Travel website for more details.If you'd like to visit the area for yourself, check out our dedicated itinerary of a recommended route.

    The Tourism of Hope: A Guide to the Key Sites of Fukushima’s Post-Disaster Revitalization
Show All (127)
Top