Mosaics

The inner, near the altar, is of the Annunciation.
It is very similar in style to the Nativity mosaic, as is clearly evident.
Nevertheless the detail is just as crisp
and fresh when viewed close-up.

St. Nicholas of Tolentine, an Italian Augustinian noted for his devotion to the souls in Purgatory 

The floor of the sanctuary and both side-altars is an intricate lacework
of beautiful tiling with the traditional Augustinian logo / crest
depicted in front of the high altar.