Krzyżtopór Castle is located in Ujazd, Poland. It was constructed between 1621-1644 by Krzysztof Ossoliński to be the largest castle in Poland and Europe. The castle's unique design included a pentagonal bastion and connections between the palace, fortifications, and garden. It was destroyed in 1770 during a rebellion. Today only ruins remain, though the castle continues to attract visitors with its unusual features and annual knight tournaments.