Hagia Sophia, currently a museum located in Istanbul, Turkey has an interesting history of secular shifts. What started off as a Greek Orthodox cathedral in the 6th century A.D, depending on the rulers, this monument underwent changes. It served as a Roman Catholic church for sixty years in 13th century A.D. After that, it reverted to being a Greek Orthodox catheral until Ottoman Turks captured Constantinople in 1453. Until 1931, it served as an Imperial Mosque before it was shut down for four years by the Republic of Turkey and converted into a secular museum.
