The Nazis revived the medieval term ghetto to describe their device of concentration and control, the compulsory "Jewish Quarter." Ghettos were usually established in the poor sections of a city, where most of the Jews from the city and surrounding areas were subsequently forced to reside. Often surrounded by barbed wire or walls, the ghettos were sealed. Established mostly in eastern Europe (e.g., Lodz, Warsaw, Vilna, Riga, or Minsk), the ghettos were characterized by overcrowding, malnutrition, and heavy labor. All were eventually dissolved, and the Jews murdered.