The Wawel Royal Castle and the Wawel Hill on which it sits constitute the most historically and culturally significant site in Poland. A fortified residency on the Vistula River in Kraków, it was established on the orders of King Casimir III the Great and enlarged over the centuries into a number of structures around an Italian-styled courtyard. It represents nearly all European architectural styles of the Medieval, Renaissance and Baroque periods.
The castle is part of a fortified architectural complex erected atop a limestone outcrop on the left bank of the Vistula River, at an altitude of 228 metres above sea level. The complex consists of numerous buildings of great historical and national importance, including the Wawel Cathedral where Polish monarchs were crowned and buried.
Wikipedia https://en.wikipedia.org/wiki/Wawel_Castle
Coordinates 50°3'17.088" N 19°56'9.986" E