Kokonoe, Oita

Steam rises from the ground at Kokonoe before you've had time to read the station signs. The whole town sits inside the mountains — not beside them, but within them — across terrain that belongs almost entirely to Aso-Kuju National Park. Kokonoe's five hot spring clusters, listed here without fanfare, carry names like Kawasoko, Yutsubo, and Hoshō: none of them famous in the way Beppu or Yufuin are famous, which means the baths stay quiet, the inns stay small. At Kawasoko Onsen, the water rises directly through the floor of the bathing pool, a single inn called Hotarugawa-sō holding the site. At Yutsubo, roughly twenty small minshuku cluster around the eastern foot of Wakamitsuyama, and the meals tend toward mountain vegetables.

The other thing the ground produces here is electricity. The geothermal output is extraordinary — the town generates far more power than it consumes, a fact that sits quietly behind the landscape without announcing itself. That same deep heat has also fed the sake and shochu trades. Yatsushika Brewery, founded in 1864, still operates in town; the building holds what is said to be Kyushu's oldest plastered relief artwork, and visitors can taste the range of what comes out of those cellars. Alongside the sake, Kokonoe produces mugi-jōchū under the name Ginza no Suzume, and kabosu liqueur from the local citrus.

Every September 9th, the Kuju Kyūtō Festival marks the nine hot spring areas that give the district its character. In May, Wakamitsuyama — called玖珠富士 for its clean conical profile — holds its mountain-opening ceremony. The Kuju range itself rises to its highest point at Nakadake, and the Chōjabaru Visitor Center, run by the Ministry of the Environment, serves as the practical entry point for the national park. This is a place where the infrastructure is modest and the land is not.