Hachiman Hells
This area is called the Hachiman Jigoku or the Hachiman Hells. Jigoku, the Japanese word for “hell,” is used to describe places like hot springs that were so uninhabitable that they were considered hell on earth. However, this ancient jigoku is mostly inactive, as the crust has moved above the magma that created these vents. As the earth above the magma moves east, more active jigoku begin to bubble up to the west of the older ones, which begin to cool as they are moved away from their heat source. Gradually, lands that were formerly inhospitable are reclaimed: Japanese silver grass (Miscanthus sinensis) and red pine (Pinus densiflora) are returning to this barren landscape.
Though older and less active, this jigoku is far from asleep; you need only to touch the warm flagstones to feel the power of the earth.
Sukunahikona Ōkami
Nearby is a rock dedicated Sukunahikona Ōkami, one of the deities who helped to create the islands of Japan. This kami is the patron deity of hot springs, as well as grain, medicine, and the tokoyo no kuni—an unchanging land of ever-present night that lies deep beneath the sea. Since Unzen’s well-being is ultimately tied to its many hot springs, a festival is held here every December to give thanks to Sukunahikona for the many blessings of the volcanoes.