But now it's neither a church not a mosque as its now a world heritage site. If you wanna go to mosque, you can walk a couple blocks west and attend the Blue mosque which was built 900 years later and, although being pretty as heck, isn't nearly as impressive from an engineering and materials standpoint.It's complicated. This is a joke about the Eastern Orthodox Church (which is different from Presbyterians, who follow a reformed theology), but whoever made this image used a poor choice of church. The Hagia Sophia was the seat of the Patriarch of Constantinople until the conquering of the city by Ottomans in 1453. The Ottomans renamed the city to Istanbul and turned the cathedral into a Mosque.