Hakodate Kokusai Hotel

函館国際ホテル There are indoor and outdoor baths (the outdoor one seems to be men-only). You can see the night cityscape and even Mount Hakodate if you go to the far corner of the rotenburo. I thought they had a sauna, but no — that's a shame. On the first day the rotenburo water wasn't hot, but they cranked it up on day two. Overall 40.5-41 in both. A nice perk: unlimited ikura at breakfast.