Restoration workers have uncovered a well-preserved, long-hidden mosaic face of an angel at the former Byzantine cathedral of Haghia Sophia in Istanbul, an official said Friday. The seraphim figure — one of two located on the side of a dome — had been covered up along with the building's other Christian mosaics shortly after Constantinople — the former name for Istanbul — fell to the Ottomans in 1453 and the cathedral was turned into a mosque. The mosaics were plastered over according to Muslim custom that prohibits the representation of humans. Some of the mosaics were revealed when the domed complex was turned into a museum in 1935, but the seraphim had largely remained covered, Ahmet Emre Bilgili, who heads culture and tourism affairs in Istanbul, told The Associated Press. Two Swiss architects saw the two seraphim during restoration work ordered by the Sultan in the mid-19th century but the figures were covered up again, Bilgili said. "It is the first time that the angel is being revealed," he said, adding that the figure had been covered with metal and plaster. "It is very well preserved." [...]

Experts would now work to uncover the second seraphim, which was also plastered over and covered by metal, Bilgili said.