Wawel Castle is a must-visit attraction in Krakow. This historic castle complex dates back to the 14th century and is located on Wawel Hill. It served as the residence of Polish kings and queens for centuries. Visitors can explore the castle's stunning architecture, including the State Rooms, Royal Chambers, and the Crown Treasury and Armory. The castle also houses the Wawel Cathedral, where many Polish monarchs were crowned and buried.