Hagia Sophia, located in Istanbul, Turkey, is an architectural marvel with a rich history. Originally built as a Christian cathedral in 537 AD, it served as the primary church of the Eastern Orthodox Church for nearly 1,000 years. In 1453, it was converted into a mosque after the Ottoman Empire's conquest of Constantinople, and later, in 1935, it became a museum. In 2020, it was reverted to a mosque. Known for its massive dome and intricate Byzantine architecture, Hagia Sophia remains an iconic symbol of religious and cultural significance, reflecting both Christian and Islamic heritage.