Question

What is this a picture of, where was it located, what was it used for?

Answer 1

That is a picture of Hagia Sophia located in Istanbul, Turkey. The Hagia Sophia served as a center for religious, political, and artistic life for the Byzantine Empire (Eastern Roman Empire). It started as a place of great importance for the Byzantines, but then became a extremely important site of worship when Sultan Mehmed II conquered Constantinople. (Constantinople is modern day Istanbul)