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.