This is the 9463rd most frequent Polish word.
wawelu
"Wawelu" is the genitive form of "Wawel," referring to Wawel Hill or Wawel Castle in Kraków, Poland.
Here, 'Wawel' refers to the hill upon which the castle is located, being a geographical name used in locative case.
Zamek na Wawelu jest symbolem Krakowa.
The Wawel Castle is a symbol of Krakow.
In this sentence, 'Wawel' specifies the location where the action took place, used as a proper noun in locative case.
Byłem na Wawelu i zwiedzałem katedrę.
I was on Wawel and visited the cathedral.
Here, 'Wawel' is used as a proper noun, representing the entire historical complex, in genitive case to indicate possession.