Prayer at the Annunciation Fresco by Fra Angelico
At the top of the flight of stairs leading to the sleeping quarters of the Convent of San Marco in Florence is arguably the most-famous, and most-copied work ever of Fra Angelico. This large Annunciation fresco (1439-43) shows the archangel Gabriel announcing to Mary that she is pregnant with the son of God.
The message at the bottom was a reminder to the monks to pray — when you come before the image of the Ever-Virgin take care that you do not neglect to say an Ave.