Thanks a lot for your feedback, guys! Much appreciated.
I feel like I'm getting closer with the city view, but I think the building / aquaduct on the right side is very unrefined compared to the rest.
@Willabee: Fixed the waterway a little bit, as suggested. Not sure what you mean by the rooftops in the front layer though.
@Decroded: I understand. It's hard to give good visual cues when it's such a tiny image and fog and rain is a central element. I guess I'll just abandon the idea of trying to illustrate that this is at very high altitude.
@Night: Thanks so much for the edit, it made a huge difference! I've tried to fix the issues where I understood what you were getting at. I also made a few changes, such as letting the light from the doors reflect more towards the viewer (vertical line) while also illuminating the road outside (horizontal line)
@Cyangmou: Well, that's because those are clouds and not mountains!
But I can understand why you'd mistake them for mountains. That's why I wasn't happy with the clouds. I wasn't able to make them look like clouds. I mean, I know how to draw clouds, but my normal technique didn't seem appropriate for this particular piece, due to the weather and light conditions. I did try to extend the rooftops of the closest houses vertically though, to adjust their perspective.