Hagia Sophia Museum in Istanbul, Turkey

This is the Hagia Sophia Museum, first commissioned by Emporer Justinian, and established as a Byzantine church about 1500 years ago. In 1453, the capitol of the eastern Roman empire, Constantinople was conquered by Ottoman Sultan Mehmed II who then converted into a mosque. It now exists as one of the largest museums and monuments in the world. I did not have time to visit but when I return someday, I will make sure to visit this incredible structure.

ayasofyamuzesi.gov.tr/en