The Soviet Union had a terrifying system for handling both criminals and political dissidents we know by one word: Gulag.
From 1930 until 1960, Russian authorities ran a tightly-controlled network of forced labor camps, known as Gulags. Gulag was actually a Russian acronym for Chief Administration of Corrective Labor Camps and Colonies, and these camps were often freezing, and forced prisoners to work and live in harsh conditions with very little food. Thriving under both Stalin and in the aftermath of WWII, Gulags housing petty criminals and political prisoners alike. The Gulag network was officially dismantled in 1960, destroying (almost) all of the prison camps, but their legacy lives on today – in memory and in the formation of many towns in the Russian Arctic.
Today most of those sites are totally gone, with little evidence remaining. However, there is a Gulag museum in Perm, and a KGB museum in the legendary Lubyanka building in Moscow that once housed the city's political detainees. Read more about them at Atlas Obscura. Link