This is the top cell of Nurmenguard, the prison of Grindelwald in Harry Potter and the Deathly Hallows. Voldemort is in the upper right corner, near a window. The window is a slight crack, as described by the book. I came up with my own texturing, where you take one of those pieces that is one across, a brick tall and any length, with the holes in the side and you take a one across flat piece with studs on top. You put the studs on top into the holes and it's done. I used lots of that technique on this set. I didn't have Voldemort when I built this set,so I substituted with another minifigure. I also entered this set in the Harry Potter Building Contest, but sadly it didn't even make top 50.
It is obvious from the size that this is most likely only the top cell of nurmenguard because in the book it describes the prison being larger. I think you should explain this is the comments. besides that I think this is a very nice build but I have seen the inside of this model and I personally believe that it is too big, it is two stories and I think that is a bit too luxurious for a prisoner. Besides that I like the outside detail and Adding random spots of SNOT (studs not on top) makes it have a weathered look to it. I also wish you would have gotten more pictures of the inside before you had destroyed it, but it is too late. Nice model Elliot!