In film noir, the city at night often provides the setting as a visual metaphor for the film. The cityscape these films portray is shadowy, secretive, and dangerous, much like the brooding mood of the films themselves. Why would the city evoke these types of moods? The answer to this is complex.

After World War II, America experienced the baby boom. While most other countries struggled to recover from the devastation of war, the United States' economy soared. All sorts of commodities were readily available that hadn't been before under the rationed War-time economy. It was a good environment in which to raise a family, and so the demand for housing quickly outstripped the supply. There hadn't been much demand for new housing during the Depression when family sizes shrunk and money was tight. With the ensuing prosperity and population boom, the United States had a housing shortage on its hands. As there was not much space to build within the confines of the city, the new housing had to spring up in what became known as the suburbs. City folk began to flee the cities to live in these new developments, most famously 'Levittown' on Long Island. While the city used to be chic, now all the money bled out into the countryside. The money the US government contributed to construction of housing mostly went to the suburbs, and as a result of the development of the major highways under Eisenhower it became easier to commute to work. Obviously, this had repercussions on the city itself and on those who remained. Buildings crumbled, the crime rate in the cities rose, and the city was associated with decay and corruption.

These factors make the city a perfect location for a film noir Another aspect of cities that directors often played up was the labyrinthine nature of city streets-- streets winding narrowly and almost nonsensically through dark alleys and fog.