By the south wall is the famous Deesis, an extraordinary 13th-century mosaic showing Christ flanked by the Virgin Mary and St. John the Baptist.
There are many other mosaics near the south wall.  
mnli hypothesis: There are many other mosaics near the south wall.   premise: By the south wall is the famous Deesis, an extraordinary 13th-century mosaic showing Christ flanked by the Virgin Mary and St. John the Baptist.