There are places where horrible things happened in history. The closer to the present, the more frightening these places seem to be. This is Petschk's palace. Unsurprisingly building. ... For the Nazi occupation of 1939-1945 there was the headquarters of the Gestapo (Secret State Police).

It is written here:
At the time of the Nazi occupation, the Gestapo torture rooms were in this building. Fighters here fought, suffered and died for the freedom of our homeland.
We will never forget their memories and we will always remain faithful to their legacy.
The street is called Street of Political Prisoners (ulice Politických věznů). It is about 100 meters from Wenceslas Square.