The Museum is set up in the former KGB headquarters where soviet crimes were planned and committed in the course of fifty years. The main part of the exposition is the former KGB inner prison preserved the way the soviet security men left it when they moved out of it in 1991. Modern expositions acquainting visitors with the loss of independence in the middle of the 20th century, repressions of the soviet authorities, and a selfless life-and-death struggle for recovery of independence are displayed on the ground and first floors of the Museum.
The Museum is founded in the former KGB building. It houses historical-documentary material about repressions against residents of Lithuania carried out by the occupation regimes (1940–1990 m.), material about anti-Soviet and anti-Nazi resistance and information about the participants in the fights for freedom and genocide victims.
The most important part of the exposition is the KGB interior prison (the inquest isolator). The former KGB execution cell is displayed, and the material in the stand shows how it was done.
Those who are interested in the history of the KGB can visit Tuskulėnai Memorial Complex. The territory of Tuskulėnai estate is the place of tragedies and cruelties of the 20th century where between 1944 and 1947 bodies of the people imprisoned and killed in the basement cells of the NKGB-MGB interior prison were buried.