In Stranger Things season 4, Jim Hopper is held in Kamchatka, a remote region of Russia containing the Soviet prison camp where he is imprisoned. The series does not give the facility a distinctive personal name, so “Kamchatka” is the standard quiz answer.
Hopper survives the Starcourt Mall explosion at the end of season 3, but Soviet forces capture him and transport him to the prison camp. There, he is forced into hard labor and eventually made to fight a Demogorgon as punishment and entertainment for the guards.
The location is important because the prison is also being used to study creatures from the Upside Down. Hopper, Joyce Byers, Murray Bauman, and Dmitri Antonov later discover Demogorgons and Demodogs there. Destroying the creatures helps weaken the shared supernatural network connected to the threat in Hawkins.
Kamchatka is a peninsula in Russia’s Far East, far from Hawkins, Indiana. A common mistake is answering “Siberia,” since the prison is Soviet and remote, but the show specifically places it in Kamchatka.