Aso Takamori Onsen

Aso Takamori Onsen is situated in the Aso area of Kumamoto Prefecture on the rim and slopes of the Aso caldera — the world's largest active volcanic caldera at approximately 25 kilometers in diameter, whose inner cone of Mount Nakadake is one of the world's most reliably active volcanoes, its crater regularly venting spectacular plumes of volcanic gas and occasionally erupting with enough force to close the crater viewing area and cover the surrounding grasslands in ash. The Aso caldera's extraordinary geography — a mountain within a mountain, the outer rim rising above the flat agricultural floor of the caldera where 50,000 people live their daily lives beneath the smoking cone — creates one of Japan's most surreal and spectacular inhabited volcanic landscapes, made even more remarkable by the vast grassland commons (Aso Kuju National Park) maintained by traditional fire-setting agriculture for over a millennium. The onsen at Takamori draw on geothermal resources from the intensely active Aso volcanic system, providing mineral bathing in the immediate presence of one of Earth's most dramatically active geological features.