Bezirk Mitte or Mitte von Berlin is the most central borough of Berlin (Bezirk is German for borough, Mitte is German for centre).
Most of Berlin's historic centre is in Bezirk Mitte. Some of the most important tourist sites of Berlin (like the Pergamon Museum, Brandenburg Gate, Charité and the Reichstag), are all in Mitte, and most were in East Berlin.