Kawayu
Address:
Ebino, Miyazaki, Japan
Category: Onsen
Note: this free outdoor onsen was shut down and converted to a foot bath as the area was developed many years prior to when I visited (May '06). Unfortunately, my information was bit old. There are some other springs in the area that are nice, and the view and hikes are amazing. This area now has a huge ecological museum, restaurant, gift store and visitor's center.
Mentioned on Jens Olsen's Site