Baptistery

The San Giovanni's octagonal baptistery has been documented at least since before the year 1000. The facade in front of the cathedral, the one where the entrance portal opens, is covered with a facing composed of bands of white and green marble, in the Romanesque-Gothic style, and dated to the 13th century.

The capitals of the pillar columns and jambs are carved with motifs of acanthus leaves, animal figures, and human heads. A single lancet window and, in the lintel, Heads of Jesus, Mary, and the Apostles complete the facade. Narrow windows are found in each facade, and a simple cornice runs around the entire perimeter.