Of all the grand palaces in Austria, Esterházy is one you definitely don't want to miss. It's second, perhaps, to Schönbrunn. The 13th-century palace was acquired by the Hungarian family in 1622 and remains in their care. Magnificent rooms like the Empiresaal (dining hall) and the acoustically perfect Haydnsaal, a concert hall named for the composer who worked for the family for 40 years, are simply stunning. If the family's wealth and importance wasn't clear, one needs simply to visit the palace chapel where they'll see the relics of St. Constantine.