View of one of the doors that lead from the exonarthex to the narthex of the Hagia Sophia. Note the two portions of the doors. On the lower one, below the “head of the arrow” the horizontal remnants of a cross that once graced the door can be detected. The horizontal crossbar was removed during the time that the church served as a mosque after the Moslem conquest in A.D. 1453.
For a brief description of the Hagia Sophia Click Here.