Remote Lamp no Yado is a place of its own: a 13-room wooden waterside village beneath a cliff. The building goes back four centuries, to when people would escape to its curative waters for weeks at a time. It's been an inn since the 1970s. Decadent rooms have private bathrooms, and some have their own rotemburo. The pool is almost superfluous.
This is a romantic destination ryokan, but not for those on a budget.