This is a very famous hot spring (onsen) bath house, well known across Japan. As you can see it was very busy so we didn't go inside, instead we went to another onsen at a nearby hotel. Its a beautiful old building, although I was surprised how small it was - I was expecting it to look more like the bath house in the animated movie Spirited Away, the design of which was based on this place. I guess I should have known it wouldn't look quite the same... http://worshipandthearts.blogspot.com/2007/06/shinto-and-liminality-in-anime.html
I apologise in advance if I'm tardy with commenting on your blogs or returning comments during the week... I will get to you though!