Mount Nakadake Crater was added to Your Favorites!
Aso-Kuju NP, Kumamoto
Claim this place to tell your story your way.
A 1933 eruption from Nakadake’s Second Crater launched a huge block onto a slope about 450 m away. A contemporary survey measured it at 7.2 m long, 5.6 m wide and 0.8 m high—an astonishing projectile, not a pebble.
Aso Takana, the region’s pungent mustard green, grows in volcanic-ash soil and highland temperature swings. Each spring, harvesters snap the tender stems one by one by hand—a tradition called takana-ori—then pickle them for takana rice.
Nakadake’s long crater is not one opening: 7 numbered craters line up from north to south. Activity has shifted between them; No. 4 was the center from 1923 to 1930, before eruptions returned to No. 1 on September 4, 1932.
The emerald pool is a temporary crater lake, not a permanent feature. In quieter spells, it can collect at about 50–60°C and is strongly acidic; when volcanic activity builds, the water may disappear.
A 7th-century Chinese chronicle, the Sui shu, already records rites prompted by Aso’s fiery activity. Today, in early June, priests at Aso-sanjo Shrine cast 3 paper-streamered gohei into Nakadake’s crater, praying for calm.
Near Nakadake’s west side, medieval Furubochu was a mountain-religion hub: from the 14th to 16th centuries, sources describe 36 temple lodgings and 52 hermitages there, serving monks, yamabushi and pilgrims.
Despite its long record of eruptions, no lava flow has been documented from Nakadake in historical times. Ash eruptions have dominated the last 1,000 years; locals call the fine black fallout yona, or “yona rain” when it falls.
A white plume is not necessarily just steam: it can contain ash too. National Park rangers have noted that Aso residents watch both plume color and wind direction, which helps them tell where ash may fall.
Around Nakadake, wind joins the volcano as a sculptor: the crater area has exceptionally rare wind-shaped landforms, including dunes. On nearby Sunasenri-ga-hama’s black cinders, a few Japanese knotweed plants still manage to grow.
