Hiking to an Active Volcano: Mount Aso in Japan

Mount Aso is the largest active volcano in Japan. Although this may sound intimidating at first – and it should as the volcano recently erupted in October 2021 – it is also one of the most accessible peaks and craters in the country.

Even though the first thirty minutes of the hike made me suffer and once again question what I was thinking when planning a hike starting at 6am in the morning, it is also one of the relatively easier hikes that I have done in Japan.

This is the account of my day hike to Mount Aso in September 2021 and the few days that I spent in the lovely Aso town at the foot of Aso-Kuju National Park. At the time of my hike, the eruption risk/alert level was at the lowest so I could get as – safely – close as possible to the crater. However, it is advisable to check the official alerts/road closures since the mighty Aso has a habit of erupting quite often.

Hiking Mount Aso – staying in Aso Town

One of the greatest things about hiking in Mount Aso is the town that you hike down back to (or take the bus if it is the grazing season). Although spending the night at the mountains in a tent or a mountain hut is a very special experience, wrapping up the day in a small, cozy and hiker friendly town can be equally rewarding. And believe me – those small towns where one can find decent and reasonably priced accommodation after a day of hiking, unlike in Switzerland or New Zealand, are not in abundance in rural Japan. Sure, there are some regions (like Yakushima) where the trails eventually lead to charming small towns but there are also many places, especially on mainland Japan, where your best bet is to transfer to un-atmospheric mid-sized city for the night. This can be a mood killer after a beautiful day immersed in nature.

So I was very pleasantly surprised to be greeted by the small, wooden and atmospheric train station of Aso – a testament to the small town charm of the town. You can see the Aso Mountain range the moment you step outside of the train station and there are no high buildings to obscure the view.

I stayed at Aso Base Backpackers Hostel. With its immaculately clean single and dorm style rooms and affordable fee policy, I say look no further. There is all day free coffee service and a large kitchen with all the utensils you may or not need to feed yourself. On the alternative, there are couple of udon or ramen shops in town along with a konbini and a very decent yakinuku place. However, one of the most rewarding aspects of staying in Aso town is the onsen that features both indoor and outdoor baths and costs around 300 yen per person. Aso feels like a perfect town designed with solo hikers in mind – picturesque enough and satisfying range of reasonable amenities.

Getting to Mount Aso trailhead

Mount Aso is home to five different peaks: Eboshi-dake,  Kijima-dake, Naka-dake, Neko-dake, and Taka-dake. I wanted to hike the trail that covers Taka-dake and Neko-dake as it appeared to be the most scenic trail and long enough to fill the whole day.

Getting to the main trailhead in Mount Aso is easy thanks to the bus service. But the bus schedule is strangely not convenient for those planning a full day hike exploring various trails along Mount Aso range. The bus departs from Aso train station and takes you Aso Senjo Terminal. There is then another shuttle bus, which will get you almost next to the caldera observation point and to the main trailhead. There is roughly four hours between the time the first bus departing from Aso drops you off at the trailhead and the last bus taking you back to Aso town. While for most hikers with average speed, it is enough time for a round trip hike up to Naka Dake –  it is not enough time for the most rewarding hike, which starts at Sensuikai Parking Lot/trailhead and ends at Aso Sancho Parking Lot and takes you through Taka-Dake, Naka-Dake and Sunasenri.

There is unfortunately no longer a public service to Sensuikai trail head and your best option is to take the train to Miyaji Station and then take a taxi or walk for 1.5 hours. Shortly after arriving at Aso station, I was lucky to meet a fellow Irish hiker from Tokyo at the train station. We decided to team up for the hike the next day and pre-booked a taxi to reach the Sensuikai trailhead (costs around 2,000 yen from Miyaji Station). It is definitely worth the cost as it allows you a full day of hiking at a very leisurely pace and to still make it to the last bus departing from Aso Senjo Terminal in the direction of Aso town.

Taka-Dake and Naka-Dake route

We started the hike shortly after 6 am am and took the bus back to Aso shortly before 3 pm. We did the following course: the section following the remains of the old Sensuikyo Ropeway, Taka-Dake, Naka-Dake and Sunasenri.

The day started with thick fog but both of us knew Japan well enough to keep hopeful for the sun come up during the day. The first part of the hike was grueling for me, but it was a walk in the park for my hiking partner – who was very kind, and waited for me and made me feel at ease. But once the first half hour was over and I got used to the rhythm, Mount Aso became a tremendously enjoyable hike with iconic scenery. One of those sceneries which one may think should require a little more effort and maybe even be less accessible. This is one of the greatest things about hiking in Japan – often experiencing spectacular sceneries even in short and not necessarily demanding hikes.

Once we finished the initial push and got on the mountain ridge (by the time some of the hikers already gave up to the fog and diminishing chance of caldera scenery), it took merely a second for the fog to lift and the sun to award us with one of the most spectacular nature sceneries in Japan – almost a bird`s-eye view of Naka-Dake crater with the fumes very vividly coming up. This was where we took our first break enjoying the scenery before we pushed for Taka-Dake – the highest peak in Mount Aso range. The trail leading to Taka-dake was rocky and quite slippery but the views were more than enough to keep me happy and motivated. 

The trail from Taka-Dake to Naka-Dake was possibly the easiest part of the whole hike. There was enough space on the peak of Naka-Dake where we joined many other hikers and took a long lunch break. The trail got much busier once we took off from Naka-Dake as most hikers just cover the trail between the bus stop next to caldera and Naka-Dake. There was a steep section in the last part of the hike leading town to Sunasenri that we had to descend, making me feel lucky that we got the ascent out of the way early in the morning.

Sunasenri – a walk on the moon

Sunasenri, the last section of the hike before reaching the bus stop, is a plantless terrain covered by volcanic sand. It is one of those otherworldly sceneries reminding you the unique terrain that you are in. It is fully flat and there is a wooden walkway, which makes it feel like more of a pleasant stroll rather than a hike. 

Mount Aso is one of the most rewarding hikes in Japan that is substantially less demanding than many other hikes with iconic sceneries (such as Japanese Alps). I would love to be back to experience the snow scenery.

For more Kyushu hikes: Hiking Mount Miyanoura in Yakushima

More hikes: Hiking in Daisetsuzan National Park in Hokkaido

For more active volcanos in Japan: Hiking Yake Dake in Japanese Alps