Cheers for that, I thought the same to be honest. Just didn't want to remove it all and it's there for something else or unknown reason.
It doesn't look like a cellar to me ........is there stairs going down to it or do you access it by a hatch in the floor ?
It just looks like the space under a suspended floor the.....the underdrawings.
No door, no steps going down ......not a cellar ! I would not think of digging it out ......mainly because of that buttress !