Hagia Sophia is a great architectural beauty and an important monument both for Byzantine and for Ottoman Empires. Once a church, later a mosque, and now a museum at the Turkish Republic, Hagia Sophia has always been the precious of its time..
The mystical city Istanbul hosted many civilizations since centuries, of which Byzantium and Ottoman Empires were both the most famous ones. The city today carries the characteristics of these two different cultures and surely Hagia Sophia is a perfect synthesis where one can observe both Ottoman and Byzantium effects under one great dome.
A 1993 UNESCO mission to Turkey noted falling plaster, dirty marble facings, broken windows, decorative paintings damaged by moisture, and ill-maintained lead roofing. Cleaning, roofing and restoration have since been undertaken; many recent visitors have found their view obstructed by a huge scaffolding stretching up into the dome in the centre of the nave.