This infamous building on vul Bryullova was used as a prison by the Poles, Nazis and communists in turn, but the small and very moving ground-floor exhibition focuses on Stalinist atrocities in the early years of WWII. Left exactly as it was when the KGB bailed out in 1991, the brutally bare cells, horrific statistics posted throughout and Nazi newsreel from summer 1941 will leave few untouched. Some English explanations.