The Old Market Square (Alter Markt) is the formal heart of Potsdam — an ensemble of civic buildings that, for most of the 20th century, existed only in photographs. The original square was destroyed in the 1945 bombing and the ruins cleared by the East German state, which replaced the City Palace with a prefabricated block. Since reunification, the square has been methodically restored: the baroque Altes Rathaus, the St. Nicholas Church, and most dramatically the City Palace itself have been rebuilt or restored to recreate the pre-war ensemble.
The result is genuinely impressive. Standing in the square, with the Church of St. Nicholas to the west, the rebuilt City Palace (now the Brandenburg Landtag) to the north, and the Museum Barberini filling the Palais Barberini to the east, it is easy to understand why Potsdam's centre was so admired before the war. The square is the natural starting point for any exploration of the old town.