East Germany's State Security Service or Stasi was responsible for intelligence gathering both at home and abroad. It spied on its own citizens, sometimes employing the friends, colleagues, and family of those they wished to keep an eye on. The museum in the former Stasi headquarters shows the office of Erich Mielke, the feared Stasi minister for 32 years, in its original dull state. Exhibitions, films and tours explain how the Stasi kept an eye on millions of citizens in the GDR and beyond.