Hagia Sophia has the strangest angels. Each of the four corners of the dome has a seraphim. Three of them have gold masks, one has a face. I couldn’t verify this information, but piecing together from several guidebooks, I suspect that the face was painted in by the Swiss Frotelli brothers, who renovated the seraphim in the 19th century. Interestingly, it was still being used as a mosque, so I wonder how that got by.