Owakudani

Owakudani, meaning Great Seething Valley, sits at the active heart of the Hakone caldera. The landscape here is roughly 3,000 years old, shaped when a volcanic collapse sent pyroclastic flows that blocked the Haya River. Today, steam and sulfurous gases rise constantly from the ground. In the Edo period, locals called this place Great Hell Hole before renaming it Owakudani ahead of an imperial visit in 1876. The valley keeps Hakone's many hot springs heated and is a site of ongoing geological research. Black eggs hard-boiled in sulfurous vents are the signature food here; the eggshell color fades within a few days.