A prison or jail/gaol.
A prison camp, especially one used to hold political prisoners.
Also GULAG: the system of all Soviet labour camps and prisons in use, especially during the Stalinist period (1930s–1950s).
A place where, or political system in which, people with dissident views are routinely oppressed.
To compel (someone) into a forced labour camp or a similar place of confinement or exile.