The cathedral face south and is approximately 54 @.@ 5 metres ( 179 ft ) wide and 110 metres ( 360 ft ) long . It consist of two bell towers , a central dome , three main portals , five naves , 51 vaults , 74 arches and 40 columns . Inside the cathedral are five large altars , sixteen chapels , a choir area , a corridor , capitulary room , and sacristy . The cathedral have approximately 150 windows .