Home to more than 8000 mountains, Japan is a wonderful destination for hiking trail lovers, but perhaps the best place in Japan for hiking is Kyushu. Its warm subtropical climate allows for an extended hiking period so outdoor enthusiasts can enjoy mountaineering in different seasons. For a unique Japan hiking experience, consider Mt. Aso. The Aso caldera is centrally located on the island of Kyushu in Kumamoto Prefecture. Mt. Aso is the second highest volcano in Japan at 1592m as well as being one of the largest calderas in the world, enclosing a total area of 380km2. Within the caldera are the five peaks of Mt. Aso: Takadake, Nekodake, Kishimadake, Eboshidake and Nakadake. Adding to the stunning view of the area are volcanic cones formed on the caldera floor.
The unique topography of Mt. Aso was formed by volcanic activities over the past 270,000 years and by a great eruption that took place about 90,000 years ago. This last eruption was so powerful that a 15cm-thick layer of volcanic ash reached all the way to eastern Hokkaido, a distance of over 1400km. Thanks to the volcanic activity and geology of the area, the Mt. Aso region is blessed with quality hot springs, fertile soil for agriculture, and excellent hiking trails. I couldn't wait to see it in person.
While the view of the seven craters of Nakadake is a popular sightseeing spot, including a colorful hot water pool in the first crater, I was encouraged, based on online reviews, to take advantage of the hiking by exploring two other recommended courses: Kishimadake and Eboshidake. It is possible to hike both mountains in one day, even if you come to Mt. Aso by bus and don’t have a full day to explore.
The morning course begins with a hike to the top of Kishimadake, which is the shorter and easier hike of the two. My guide, Kawahara-san, was very considerate and gave me the latest trekking map which he himself made. Even though I don't do a lot of mountaineering, I had a pleasant hike to the top as parts of the path are paved, with easy-to-climb stone steps.
Normally, from the parking lot, it takes only about 40 minutes to reach the top, but it took us longer as I took frequent stops to enjoy the majestic scene before me.
I noticed, in addition to the vast grasslands, an incredible number of cedar trees. My guide said that farmers planted the cedar trees seventy years ago in order to boost the local economy through logging and other industries. The combination of grassland and cedar trees seems like a scene out of The Lord of the Rings. We finally reached the summit (1.4km) and the panoramic views of Kusasenri-ga-hama, Nakadake, and Eboshidake were simply breathtaking.
After replenishing my energy with an outstanding Akaushi beef bowl for lunch, we then started our hike to the top of Eboshidake. It's 1.9km to the top and the route is not as well paved as Kishimadake, so you will have to be in moderately good shape to make this climb. I took a couple of brief stops to catch my breath, but those brief stops were part of the highlight as my guide patiently shared interesting information about the area. The trail to the summit can be challenging depending on the weather, so I recommend that you bring your own hiking boots.
The view from Eboshidake's summit is different from the one I saw earlier at Kishimadake but both were equally magnificent. In addition to a view of Kusasenri, I was able to look out over Nakadake's crater and a ravine that cuts through the caldera. I couldn't quite see down into the crater, but I did see the backside of the rim, which isn’t possible from ground level.
From the top of Kishimadake, I was treated to a breathtaking aerial view of Komezuka. At a relatively young age of 3,000 years, Komezuka is still a cute baby mountain. It has a perfectly shaped volcanic cone and because it is young, it is smooth all around, unlike the older mountains I saw whose faces have been scarred by the forces of nature over the centuries. The kome in Komezuka means “rice” and thus, appropriately named as the mountain looks like a bowl of rice turned upside down.
The Mt. Aso region has a large number of craters due to multiple volcanic activities. On top of Mt. Kishima is an impressive old crater called Oike that was formed 4,000 years ago and has a diameter of 250m. It is difficult to gauge the scale of the crater by itself so my guide shared an analogy I could understand - sports. If you are a sports fan, you can imagine an entire stadium can be built into this crater! The route along Oike is also popular for school excursions for elementary school children. Looking at the trails, I can easily imagine parents building great memories with their children as they hike up and down Mt. Kishima.
Hiking up two mountains in one day can be tiring so I treated myself to a delicious Akaushi beef bowl meal. Akaushi beef is a rare type of meat due to the fact that Kumamoto cattle graze around the sacred volcano of Mt. Aso and its farmlands and get lots of exercise in the great outdoors. Akaushi cattle excel in growing, providing us with healthy lean meat with fat that is evenly distributed. It is this marbling that contributes to the excellent flavor and tenderness. This beef was one of the most succulent foods I have ever tasted. The combination of homemade sauce, homemade spicy miso, and a soft-boiled egg was outstanding!
Kusasenri-ga-hama is a uniquely shaped grassland crater area that contains another small 1km diameter crater within it. The larger crater of Kusasenri-ga-hama has formed from a volcanic eruption 30,000 years ago. Magma flowed out onto the ground and formed a dome in the crater which later erupted, forming the current double-layered crater. Six kilometers underneath Kusasenri-ga-hama is an enormous magma chamber so my guide jokingly told me to talk quietly while walking around the grassland so as not to disturb it. I admired a splendid view of Kusasenri-ga-hama from the top of Eboshidake.
Even the most experienced hiker can benefit from taking along a Japanese guide on these treks. My guide was local Kumamoto resident Tetsuo Kawahara whose expert knowledge of the area greatly enriched my experience of Aso Kusasenri. During our hike, the friendly Kawahara-san stopped to assist other hikers on the trail as well. As icing on the cake, Kawahara-san presented me with gorgeous pictures of the area that he had taken in different seasons. You can book a private guide at the Aso Volcano Museum located next to the parking lot. Make sure to call in advance to ensure a guide is available on the day you want to hike.