Mount Aso - Christopher E. Brennen

ADVENTURES AROUND THE WORLD
© Christopher Earls Brennen

Hike C9. Mount Aso, Kyushu, Japan

Hiking time: 3 hours
Estimated hiking distance: 2 miles
Elevation gain: 1000 feet
Topo Map: Geospatial Authority of Japan Online Map
Permit: None required
Warning: Nakadake, Mount Aso, is a very active volcano that erupted in 2021 and 2016 and many times before. The area around the First Crater is often closed off to protect visitors from the ejecta, poisonous gases and flying lava rocks. Because of the latter, concrete shelters have been built around the rim. Even when it is open to visitors there is still significant danger of which the hikers must be aware.

Characteristics

Mount Aso is a very large volcanic caldera in Kyushu formed by a number of huge volcanic eruptions in the distant past. The caldera measures about 15 miles across and is ringed by a number of very active volcanoes that seem to erupt about every five years. One of the most active of the craters is known as Nakadake, First Crater. The hike described below starts at the rim of the First crater, and proceeds around it before climbing to the 4941ft summit of Nakadake and the 5223ft summit of Takadake. From there you may choose to descend north to the old visitor center at Sensuikyo or to the First Crater where you started.

First Crater

Trailhead

The trailhead for the hike is the Nakadake First Crater at 39^o52.91'N 131^o5.03'E (elevation 4200ft) which is accesible by car when the crater area is open (see above). There are two options for this hike. The simplest is the out and back from the First Crater to Nakadake and perhaps Takadake. The second option is to set up a car shuttle at Sensuikyo for a one way hike.

Hike

From the spectacular First Crater at 39^o52.91'N 131^o5.03'E (elevation 4200ft) proceed along the rim formed by the other craters. Pass the aforementioned concrete shelters, hiking south and west. Leaving the craters you proceed along the board walk across the Martian landscape of the old crater Sunasenri-Ga-Hama. Then climb steeply up a broad ridge and under a cliff following the well-worn path toward the summit of Nakadake. It takes about 75 min to reach the Nakadake summit at 39^o53.01'N 131^o5.82'E and an elevation of 4941ft.
Here there are two options. The first is to hike further west along the ridge to the slightly higher summit of Takadake at 39^o53.06'N 131^o6.24'E and an elevation of 5223ft. This sidetrip will take about 30 min each way.
To continue it is best to return to the Nakadake summit and take the cliff top trail toward Sensuikyo. A short way along this trail you will come to the Crater Observation Platform with a spectacular view of the volcanic craters. Continuing the descent you will come at 39^o53.37'N 131^o5.55'E and an elevation of 4200ft to the upper station of the cable car system that rose to this point from Sensuikyo before it was ruined in a volcanic eruption and subsequently dismantled. This location (called Kato Highashi on the map) is just south of a 4367ft peak labeled Mt. Narao (39^o53.37'N 131^o5.55'E, elevation 4367ft). From Kato Higashi you descend roughly parallel to the cable way route to the tourist area and car park at Sensuikyo at 39^o53.92'N 131^o6.17'E and an elevation of 2956ft. Near this destination you cross a pretty stream with a nice grotto. The descent from Nakatake to Sensuikyo will take about 75 min.

On the summit of Nakatake. Mount Aso, Kyushu

Addenda: My thanks to Professor Inoue of Kyushu University who, with his wife and daughter, drove me to the First Crater and collected me at Sensuikyo on Aug.24, 1996.

Last updated 9/1/00.
Christopher E. Brennen