A little try.
Awesome work, hug0! The top structure looks like it isn’t directly on top. Is it on purpose or some sort of optical illusion?
The only thing really is that it might be a little too obvious where the edge of the scene is. I don’t see much for the Focused Critique section honestly since it looks quite close to a completed state.
Thanks, carpetudo. The top structure doesn’t touch anything, only the stairs. 
Hi, Ace Dragon! I don’t understand what you mean with “where the edge of the scene is”.
I posted here because it was my first try with this kind of post production in photoshop. I used to use just color correction, curves and this kind of resource.