I used to study architecture, and about ten years ago (after drinking too much) decided to visit an architecturally famous but rough estate at night. (It was Robin Hood Gardens.) I walked around and the place was, most significantly, empty. I got hailed aggressively by some guys but a fast walk was enough to get out of there without being confronted.

There is danger, all right, but I think you would probably agree that it's not the obvious, conspicuous risks that lead to violent crime. It's the places that don't seem dangerous where it happens, because those are the places where victims are present and not focusing on their safety.