It looks like Istanbul just got its newest angel.

In the famed Haghia Sophia — originally a Byzantine basilica — experts have just uncovered a mosaic face of a six-winged angel that lay hidden for more than 160 years under a mask of paint and metal.

The image, believed to be at least 700 years old, was uncovered during restoration work on the temple’s interior, national media reported. To their surprise, the mosaic, located on the structure supporting the dome, was exceptionally well preserved.

Haghia Sophia, originally constructed as a church between 532 and 537 A.D. on the orders of the Byzantine Emperor Justinian, was the largest cathedral in the world for nearly a thousand years and is considered by many to have changed the history of architecture. In 1453, when the Ottoman Turks conquered Constantinople, the cathedral was converted into a mosque and its Christian mosaics were covered up in line with Muslim custom. Many were revealed after Haghia Sophia was turned into a museum in 1935, but not the angel.

The six-winged figure is though to depict seraphim, celestial creatures said to be the caretakers of God's throne, who belong to the highest order of the hierarchy of angels.

According to Turkish daily Hürriyet, the last person to see the image of the celestial being is believed to have been the Swiss architect Gaspar Fossati, who led the church’s reconstruction under the reign of Sultan Abdulmajid (1839-1861).

The Haghia Sophia’s High Academic Council and the Council for the Monuments will now try to determine the mosaic’s exact age.