The Romans also had sort of strip mall deserts along the roads approaching major cities, all littered with fast food joints, family shrines, and a variety of businesses illegal within the city limits.
This is the kind of thing one picks up reading historical novels. The authors tend to do a lot of research, and we know a fair bit about Rome, its neighborhoods and its underground. I was always partial to the Lindsey Davis “Falco” books which had a private informer as the primary character.
