A full reproduction of this stove can be seen in the next picture.
I'm fascinated by the stoves that used to heat these old palaces; many of them in newer castles and palaces (17th-18th century) are works of art in themselves. But while we were touring this particular 13th-14th century palace, I was wondering where the stoves were, and found original tiles and explanations in the museum part of the building and reproductions in the individual living quarters. Apparently, the idea for this method of heating came from Switzerland, but beyond that I haven't learned much.