Here the single indoor triangle-shaped bath is built against some giant rocks. It appears that these rocks were naturally here, and the bathhouse was built around them. Not sure if that is true, but it looks cool and gives the place its name. Of the three day-use baths here, this is the most stylish. So, go here for the rocky aesthetics but be aware that this one has a lot of stairs. It's a bit cramped and small in the changing room, so it might not be the best option for the mobility impaired.