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.
After 160 years of darkness, Seraphim's face is in daylight.
There are 4 seraphim mosaics ( God's protector angels with 6 wings) on the 4 pendentives that carry the dome. The 4 seraphims' faces were covered with 6-7 layers of plaster for almost 160 years during the sovereignty of Ottomans. The last person who saw the faces of the Seraphims was the Swiss architect Gaspare Fossati while he was holding the restoration at Hagia Sophia in 1840s. With a 10 day hard work, experts managed to take off the 7 layers of plasters and reveal the face of one of the seraphims.
The 16 years old scaffold that was standing on the southeast quarter of the dome for reconstruction purposes has been unstitched to be set up to northeast quarter. The certain age of the mosaics is unclear however they are known to be older than 700 years.