We spent a fantastic two-day stay at the Kagaya onsen in Wakura (on the west coast of Japan).  There are two primary activities — relaxing in the thermal baths and eating.  Probably more the second than the first.  The Wakura area is famous for its fresh seafood and the elaborate meals bring almost every conceivable variety and preparation one could imagine.  Some highlights below (but there was much more in only our 2 days).