There was a surprisingly fine hamam (bath house). In its back, along the wall to the right, was the place where the fire was made to warm the water. I took a closer look, never having seen that part of a hamam before.

This is the place, there seemed to be a copper ring, maybe to prevent the chimney from cracking due to the heat. I also noticed that there are several channels through which the heat could enter the building. My guess is: to heat the floor? If a hamam expert reads this: please inform me somewhat on the system.