Built as a Tsarist military prison in 1900, Karosta later served the Soviets and Nazis, earning a reputation for brutality—few who entered left unscathed. Since its closure in 1997, it has become infamous for paranormal activity: guests report cell doors slamming, spectral guards in uniform, and sudden temperature drops during overnight “prisoner experiences.” Featured on international ghost shows, it is often called one of the most haunted prisons in Europe.