Nakadake Crater No. 1 Viewpoint was added to Your Favorites!
Aso-Kuju NP, Kumamoto
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Nakadake’s 7 craters stretch nearly 900 m north–south, and the active vent has wandered: No. 4 dominated from 1923 to 1930 before activity returned to No. 1 on September 4, 1932. It has remained there since.
The emerald pool is no permanent lake: it forms inside Crater No. 1 during relatively quiet spells. Its strongly acidic water is usually 50–60°C, a vivid reminder that this beautiful pond sits inside an active volcano.
Just 1–2 km west, the flatland around Nakadake once held a remarkable mountain-sanctuary community: 36 Buddhist lodgings and 52 hermitages stood there from the 14th to 16th centuries, housing ascetic monks.
Aso City records that the crater pool was revered as “Shinreichi,” the sacred pond of Takeiwatatsu-no-Mikoto. The crater-facing upper shrine held a June “crater-calming” rite, casting sacred paper streamers into the volcano.
Eight shelters near the crater viewing area were built in 2020–21. Each dome is 6 m wide, has 50 cm-thick walls and a double roof with sand between its layers, and can shelter about 60 people.
On the restricted upper slope inside the crater, Japanese knotweed survives with tiny shoots and unusually long underground stems. In fertile ground, the same plant can grow over 2 m tall—a striking change in a harsh volcanic habitat.
Aso’s E Zone, northwest of Crater No. 1, offers a close view of nearly the whole crater—and the sound of its fumaroles. It opens only when the usual B1/B2 areas are closed and E Zone’s own gas and wind stay below safety limits.
