I think you did a very fine job with it. You can always look closely at small details and point out improvements, but you know, that only happens if first “the picture works.” And this one does. It’s a nice, well-composed shot and well executed.
To me, the main comment I would make is that “a stonemason probably would not leave the block work finished-out like that.” You notice that beneath the arch the edge of the wall is kinda “just there,” continuing the blockwork and using some very thin blocks on the left side. Probably the stonemason would have set a column of blocks on the left and right-hand sides beneath the arch, and would not have used blocks of unequal thinness. A Roman mason would have done it one way; a Greek another; a German another way again; all according to the customs of his location and craft. The mortar-lines probably also would not be so thick; this appears to be a texture taken from concrete block work.
None of these points ‘scream out’ from the picture, but they are the sort of detail that research into the techniques of a stonemason would have revealed. Had this been done as a commercial shot, a game set, or especially a movie project, they would have been a gaffe.