When visiting Krakow Poland, you really must make time to visit Zamek Krolewski otherwise known as the Royal Castle.  The structure dates back to the early 16^th century.  King Sigismund the Old hired Italian artists to design and build his castle, which was nearly destroyed by fire near the end of the 16^th century.  You can still see parts of the Renaissance castle such as the arcaded courtyard.  In the 17^th century, the castle was nearly destroyed during the Swedish wars but in 1905, a Policy society bought the castle and began to restore it.  The castle was again almost destroyed in 1945 by the Nazis but managed to, once again, remain mostly intact.