This was the winter residence of the Esterházy family, who helped the Habsburgs establish their rule in Hungary. From 1663 to 1672, on the site of a medieval fortress, Prince Paul Esterházy commissioned Carlone to build this quadrilateral framing a cour d'honneur; a neo-Classical portico and a terrace were added to Schloss Esterházy around 1800. The Esterházy Museum, the state rooms and Haydnsaal (Haydn Hall), where the musician led the prince's court orchestra, are open to visitors.