When we want to refer to the sevillian Cathedral, we always name it La Giralda.
La Giralda is the name of the tower, once minaret of an arab mosque built on roman ruins.
It was the second biggest arab minaret in the ancient times of the arab conquest. The first one was in Bagdad.
The rest of the cathedral nowadays is christian, nothing else remains from the arab times.
It is called La Giralda after the weather vane on top that used to spin around a lot. After all, spining in spanish is "girar".