A place where terror is tangible, a place of remembrance and a warning from history, the “Topography of Terror” exhibition is located on the site where between 1933 and 1945 the principal instruments of Nazi persecution and terror were located: the headquarters of the Gestapo, the high command and security service of the SS, and from 1939 the Reich Security Main Office.

With more than a million visitors each years, it is one of the most frequently visited museums and memorial centre in Berlin.

History of the site:

In summer 1933 the Gestapo secret police began using what it called a “house prison” for political inmates. The prisoners were interrogated and tortured in the offices, and most of them were then sent to prisons or concentration camps. A total of 15,000 opponents of the Nazi regime were imprisoned by the Gestapo here. Among them were Georg Elser, who attempted to assassinate Hitler, as well as members of the Red Orchestra and Kreisau Circle resistance groups, and members of the 20th July plot.
After the war, the area was left derelict. Not until 1987, for the city’s 750th anniversary, was the first exhibition organised. It was originally a temporary one, but such was the interest from Berliners and tourists that a new documentation centre was eventually built.

source and more information: https://www.visitberlin.de/en/topography-terror