Wilanów Palace was build in the 17th century for King John III of Poland and is considered one of the oldest museums in the country. Its stunning baroque interior and exterior survived the destruction of Warsaw during World War II and today the former royal collections of paintings (including works by Peter Paul Rubens and other masters), porcelain, and expert works in gold and silver. You can visit the palace and the impressive park separately or in one ticket, and a guided tour is highly recommended.