Kumamoto Hidden Gems

Kumamoto is built on and around a volcano. Aso's caldera is one of the largest active ones in the world — around 25 kilometres across, with towns, roads, rail and rice fields inside it, so you do not view the crater from outside so much as drive across its floor toward the cone still venting in the middle. The same volcanic geology filters the groundwater, and Kumamoto City runs entirely on it: the tap water is spring water, which is unusual for a Japanese city of that size. The castle was one of the great fortresses of the country, with curved stone walls designed to be unclimbable, and it was badly damaged in the 2016 earthquakes; restoration is a decades-long project and parts remain closed or viewable only from walkways. Kurokawa, in the northern highlands, is a hot-spring village that agreed to a shared architectural standard and a common bathing pass.