Got lost trying to find the onsen furthest away from the house. Tried to be adventuresome... But found a nice old fashioned wooden bathhouse. Brazenly parked illegally in front of the onsen and got an earful from the lady working the counter when we got out of the bath. Needless to say, there is no parking. But it was a nice "historic" bath. 100 yen.
Then onsens on the other side of town are cheap. Watch out for more "adventures"