Hagia Sophia is a former Orthodox patriarchal basilica, later a mosque, 29 May 1453 until 1934; it was opened as a museum on 1 February 1935.

This is the most famous image of Istanbul since the year 537 CE and a masterpiece of byzantine architecture. The mosaics are astounding, as is the huge Ottoman ceiling dome. Its design represents Paradise and it conveys the sensation of being suspended in heaven.

Because Byzantium was strongly under the intluence of Rome at the time of the construction of the Hagia Sophia, this structure is an amalgam of the magnificence of Roman architecture with the standard church architecture of the Byzantines. The original mosaics of the church were severely damaged by the Iconoclasts, but new mosaics replaced the former in the 9th century after the period of Iconoclasm had disappeared.