San Giovanni in Fonte, Baptistry
From the font
This octagonal structure, a reputed gift of Constantine, is next to the papal archbasilica of San Giovanni in Laterno, the official cathedral of the pope as Bishop of Rome. It was for generations the only baptistery in Rome and was a model for other churches. Octagonal in shape, a symbol of regeneration and the Resurrection, it once housed a large octagonal basin for baptisms by total immersion. It is dedicated to its twin patrons: St. John the Baptist and St. John the Evangelist. Pope Leo the Great termed it: "...the fount of life by which the entire world is laved."