Hagia Sophia, located in Istanbul, Turkey, is a monumental building with a layered history as a cathedral, mosque, and museum. Its construction was completed in AD 537 under the Byzantine Emperor Justinian I, becoming one of the grandest churches in Christendom and a masterpiece of Byzantine architecture with its massive dome and rich interior decoration. After the Ottoman conquest of Constantinople in 1453, it was converted into a mosque; in more recent times, it has functioned as a museum and again as a mosque. Its architectural innovations, mosaics, and complex history make it a symbol of the meeting of Christian and Islamic civilizations and a UNESCO World Heritage site.
Location: Istanbul, Turkey
Coordinates: 41.0085046, 28.9800112
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