Ippommatsu Onsen Ippommatsu Tatsu Kono Yu

A genuine wild bath (野湯, noyu) tucked into the Nyuto mountain trail, about a 30- to 45-minute walk from Kuroyu Onsen. The small stone-lined pool sits right beside the hiking path, fed by a sulfurous spring that seeps up through the rock, the water runs clear at rest but turns milky white when you stir up the sediment on the bottom. Temperature is adjusted with a hose drawing cold stream water. No facilities whatsoever; bring everything you need.