Wawel Cathedral of St. Satnislavus and St. Waclaw was funded by King Wladyslaw Lokietek in the 14 th century and is the third church erected on this spot. The first Cathedral was built in the year 1000. The Cathedral was a place of coronations and burials for the kings of Poland.
Here is a link about Wawel Cathedral in English and possibility of virtual trip http://katedra.nazwa.pl/en/
In my opinion is unique place with rich history.
Enjoy the trip.