The former headquar­ters of East Germany’s Min­istry of State Secur­ity (“MfS” or “Stasi”), a secret police and intel­li­gence agency from 1950 to 1989, are par­tially open to the public. Stasi-Museum in Berlin-Lichtenberg is worth a visit for every­one inter­ested in modern history. 

If you haven’t seen the movie “The lives of others”, you should (YouTube has a few snip­pets). A good primer for vis­it­ing the Stasi headquarters.

(* Head­line from a speech by Erich Mielke on Novem­ber 13, 1989 at People’s Chamber (“Volk­skam­mer”) in Berlin / YouTube)