The lush and active volcano of Kyushu
Mount Aso is Japan's biggest active volcano, located in the heart of Aso Kuju National Park in Kumamoto Prefecture on Kyushu Island. The volcano culminates at 1,592 meters above sea level with a circumference of about 128 kilometers. Its frequent eruptions are constantly supervised, and the mount is closed to the public at these times.
Eruption of Naka-dake Crater on 20 October 2021: Volcanic activity alert raised to level 3. Approaching the volcano within a 2km radius is prohibited due to possible pyroclastic flows and projections of incandescent materials.
Following the April 2016 earthquake in Kumamoto: traffic on roads and rail is still disturbed + Naka-dake was re-opened on February 28, 2018, but its cable car is still closed. Train traffic resumed on August 8, 2020.
Due to intense volcanic activity, the Naka-dake crater is regularly closed to public.
Volcanic activity alert raised to level 2 on 15 July 2020. Check current restrictions here.
Mount Aso is actually a volcanic complex that includes about fifteen other volcanic peaks as well as Aso, with a population of about 100,000 inhabitants. Its caldera, a vast plateau made by previous eruptions, measures 25 km from north to south and 17 km from east to west.
We count 5 main domes:
- Naka-dake: 1,506m, the most active and popular
- Taka-dake: the highest with at 1,592m and with a crater 600m in diameter
- Neko-dake: 1,408m, considered the oldest one
- Kijima-dake: 1,321m
- Eboshi-dake: 1,337m
The caldera was formed between 300,000 and 80,000 years ago during the four eruptions, called Aso 1, 2, 3 and 4. The whole complex has experienced more than 160 eruption events since the year 533, as confirmed by documents from that time. One recent eruption happened on September 14th, 2015. On October 8th, 2016, volcanologists witnessed an explosive eruption on a peak that had been in a sleep status since 1980.
Despite some dangers, mostly due to sulfur gas, Mount Aso remains accessible to tourists. In the 1990s, concrete bunkers were built around the crater of Naka-dake to allow hikers to shelter in case of eruption. In that case, access would be forbidden to the public up to one kilometer around the volcano 🌋, and the cable car 🚙 giving access to it would close. Before scheduling a hike there, it is wise to check for official information related to the volcano’s status.
Please note that the serial earthquakes that impacted Kumamoto in April 2016 still affect the whole site. Naka-dake and its blue lake were closed for a time but opened again in 2018. It is advised to choose hiking trails on other peaks, such as Taka-dake, which offers a magnificent view of the surrounding landscape. Less sporty tourists will have an easier climb at the lower Kishima-dake mount.
Another main attraction, the vast grass-covered plain Kusasenri-ga-hama welcomes cows and horses who come here to graze. Horseback riding is possible, but not in winter. On the opposite side is the Aso Volcano Museum and research center, with two real-time cameras 📷 filming inside the crater.
From this high plateau, we can admire one of the most emblematic landscapes of the area: Komezuka, the all-green symmetrical crater, which can be photographed from the two roads crossing the caldera. For a comprehensive visit, we recommend stopping at one of the hot springs, such as Akamisu, Aso-Uchinomaki, Jigoku, Tarutama or Yunotani-Aso.