Banlieue
A banlieue in France is the name for a suburb of a large city, or all its suburbs together.  Most of them are outside the official boundary of the city. They are now mostly full of low-income housing projects with large numbers of immigrants and high levels of crime and unemployment. Not all suburbs are full of poor people, but those are the places people usually mean.  There have been several riots in banlieus about police racism.