Oowakudani is the source of the sulfurous waters piped down to the Hakone hot springs resorts. It’s also a popular destination in its own right, due to the terrific views (1, 2, 3, 4 ) and novel cuisine.

The current name for the place translates as “great boiling valley” (大湧谷). This was an early example of tourist marketing, since until they heard that the Shogun was going to come up and take a look, the locals just called it “the big hell”.