Sulphur steam
From the vents.
Joli Rumi — CC BY-SA 4.0 · David Monniaux — CC BY-SA 3.0 · Suicasmo — CC BY-SA 4.0 · 663highland — CC BY 2.5 · User: (WT-shared) Jpatokal at wts wikivoyage — CC BY-SA 4.0 · Steve Collis from Melbourne, Australia — CC BY 2.0 · Christophe95 — CC BY-SA 4.0 · Batholith — Public domain
A volcanic valley in Hakone whose name means «Great Boiling Valley», with sulphur vents and hot springs. It was created around 3,000 years ago by an eruption of the Hakone volcano. From the ropeway station and its viewpoint, visitors look over yellow and grey slopes wreathed in steam, with Mount Fuji behind on clear days. The smell of sulphur is strong. The valley is famous for kuro-tamago, eggs boiled in the mineral-rich spring water until their shells turn black; local lore says eating one adds seven years to your life. They are sold at a shop by the station. Visitors arrive on the Hakone Ropeway from Sōunzan or Togendai, or by bus; the old footpath up to the egg-boiling site has been closed since 2015 because of volcanic activity. The volcanic alert stood at level 1, the lowest, in late September 2026, per visitor guides, but access can be restricted if activity rises, so check before you go, and people with breathing problems should not linger in the fumes.
From the vents.
Black eggs.
Behind, on clear days.
Hakone, on the Hakone Ropeway line
Eggs boiled in the mineral-rich hot springs until their shells turn black; local lore says each one adds seven years to your life, and they are sold by the ropeway station.