HOW TO DESCRIBE ARCHITECTURE?

The Wawel Castle is probably the most important site in Krakow. It is thought to be a symbol of power, because for centuries it was the residence of kings of Poland ("of kings of Poland" is correct. Speaking, it's easier to say, "of Poland's kings."). However, in this these days it is a turistic tourist attraction.
The Wawel Castle is 7040 metres squared (It is more common to write "7040 m²"). It is located on the hill, near to the Wisła River. Generally, the architecture is gothic, but the building contains a lot of different styles within.
The Wawel Castle was built at Kazimierz III the Great's behest. That place (I suggest saying, "The castle") survived many difficult periods in Polish history. From that forward The Castle was has been renovated many times. According to the legend ("According to legend" is a set phrase. You don't put "the" after legend unless you have reffered to a legend earlier in your story/essay or unless you say, "According to the legend of ------(insert the title of the legend)----"), the a dragon lived in the a hole under the Castle. Nowadays, the dragon monument stands in that place.

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