Fukenoyu Onsen

Perched at 1,100 meters on Hachimantai, Fukenoyu is surrounded by steaming vents and sulfur-scented ground, the whole hillside feels alive. The outdoor wild baths (野天風呂, noten-buro) are the reason most people make the trip: a mix of box baths, barrel baths carved from old miso casks, and rock pools, some mixed-gender, all under open sky with fumaroles venting in the background. Indoor baths run two different spring types, simple acidic and alkaline, and the inn has been here since the Edo period.