This is where I went to check that this side has no outside chimney. So, here’s my theory–I think this is an old one room cabin with a big brick house built around it. The chimney is enclosed to cover over whatever they had to do to put another fire place on it. My guess is that, if you went inside, you’d see that this corner room isn’t connected to the other room inside, because who could cut through a wall?
Tiny Cat Pants 