The Royal Castle in Warsaw (Zamek Królewski w Warszawie) in Castle Square. During World War II, Hitler and his cronies decided to steal all of the art, fireplaces, and even the floor before blowing up the place, but apparently the castle staff defied the Nazis and secretly organized to save many of the pieces . . . including the floor. WTF, how do you hide a floor from the Nazis?
Photo taken at: Royal Castle, Warsaw