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Daisetsuzan NP, Hokkaido
Claim this place to tell your story your way.
The crater’s floor still vents volcanic gas: hydrogen sulfide killed 2 hikers in 1958 and 2 more in 1961. Its interior remains off-limits, so the rim trail is the place to look down—not enter.
The caldera-forming eruption came in 2 acts: at nearby Tenninkyo, stream gravel separates 2 Ohachidaira pyroclastic-flow deposits; magnetic evidence suggests the eruptions were roughly a century apart.
One rim summit carries a human story: Matsuda-dake is named for Matsuda Ichitarō, who surveyed the Ishikari River headwaters in 1857 with 4 Ainu guides—11 years before the Meiji era began.
Kamikawa Ainu revered the Daisetsuzan peaks around Ohachidaira as Kamuy Mintar, “the garden where the kamuy play.” The name embraces a sacred mountain world, not just the crater.
Beneath Ohachidaira’s floor lies an ancient lake archive: researchers found over 60 m of lake sediment, whose pollen records 4 vegetation zones in a cold climate, including one especially frigid phase.
Late snow creates a second spring below Ohachidaira Viewpoint: in mid-July, fresh Chinguruma (mountain avens) emerge where snow has just melted, even while flowers in nearby areas are already past peak.
One eruption here reshaped valleys far below: pyroclastic flows spread along the upper Ishikari and Chubetsu rivers, then welded and cooled into the column-jointed cliffs at Sounkyo and Tenninkyo.
