Staying in an old place in Union Pier Michigan for a 4 day break from the world and this is in our room. Wood or coal? The young lady at the desk has no idea.
I’d guess it is a masonry heater and would need wood split fine so as to make a hot fire to charge the stone.
So it is a wood burner I found out this morning. There are 9 of them throughout the buildings and they are all fully functional. Small fire box for small wood but once its hot it stays hot. It's the first time I've seen them in the U.S. I've seen lots of them in various places in Europe, mostly in the Alpine regions.