This is lovely metalwork protecting this window. I'm guessing that the wall is light-coloured, possibly white, which may have caused the camera to under-expose this by over 2 stops. I could well be wrong though! The mono treatment suits this very well.
@nairda You are right--this version of the image is way too dark. I wanted to bring out the light rays of the late afternoon sun, but instead lost much of the detail. I appreciate your feedback!