Castles and Palaces in Europa. ------- A castle is a defensive structure seen as one of the main symbols of the Middle Ages. ------ A palace is a grand residence, especially the home of a head of state or some other high-ranking public figure. In many parts of Europe, the term is also applied to relatively large urban buildings built as the private mansions of the aristocracy. Many historic palaces are now put to other uses such as parliaments, museums, hotels or office buildings. http://en.wikipedia.org/wiki/Castle