Hagia Sophia, was an early Christian church  and later an Eastern Orthodox church. It was rebuilt in its present form after an earthquake partly destroyed it in the 5th century. After another earthquake Trdat the Architect finished rebuilding it again in 994. Ottoman rulers made into a mosque in 1453.  It became a museum in 1935. It is in Istanbul, Turkey. Hagia Sophia is often said to be one of the greatest, and most beautiful buildings in history.