The first mosaic site we visited is located right behind the building that we stayed in. It is a baptistry, where Christians of the Arian persuasion went to be baptized. Arianism was eventually eradicated by the not-so-tender mercies of the winning theological party (Trinitarians), but the baptistry was preserved. It is a relatively simple and small brick building with a dome covered by a mosaic. In the center is a beardless Jesus, flanked by John the Baptist on the right, and the river Jordan personified on the left. We spent a lot of time looking at the faces of the Apostles; each face is different and you can almost imagine their characters from the way they are depicted.
The rest of the building is now bare brick, and, like other old buildings in Ravenna, it is sinking. I include a picture of a 'pop-up' gallery just across the alley from the baptistry; they were selling skateboards, 'street' art, and small images like the big red fellow in the picture.