The vast complex of the Imperial Palace, the Hofburg (or Burg), lies along the Ringstrasse.
It consists of a number of buildings, of various periods and styles, enclosing several courtyards; the oldest part dates from the 13th century and the latest from the end of the 19th. The Hofburg abounds in magnificently appointed private and state apartments. It houses the imperial treasury of the Holy Roman and Austrian empires, the Austrian National Library, the Albertina and several other museums, and the Spanish Riding School. The state apartments in one wing of the Hofburg serve as the offices of Austria’s president. Close by stands the Privy Court Chancery (1716–21), where the Congress of Vienna met after the Napoleonic Wars.