The Baptistery of San Giovanni is one of the monuments of Piazza dei Miracoli, in Pisa. It is located in front of the western facade of the Cathedral of Santa Maria Assunta. An imposing structure: Eight monolithic columns alternating with four pillars compete in height with those of the Cathedral. A women’s gallery, accessed by a spiral staircase, overlooks the central space giving a particular perspective from which to observe the baptismal font of the Lombard school, the pulpit by Nicola Pisano and the intricate geometry of the floor of Arab matrix.
The largest Baptistery in the world
It is the largest Baptistery in Christendom. It has a circumference of 107 m and a height of 55 m, the same diameter as the facade of the Cathedral. Its foundation dates back to 1152, but its construction (financed by the Pisans who self-taxed every year), lasted for over two centuries, with different architects to direct the work: from Diotisalvi to Nicola and Giovanni Pisano, who added the crowning of the gallery and the roof.
Baptistery, interior, dome
The Pisan Romanesque facade features a very rich decoration of sculptures, many of which have been transferred to the nearby Museo dell’Opera del Duomo (reopened to the public in 2019 after a masterful renovation). The portal of the early thirteenth century facing the Cathedral is the work of sculptors of the Greek-Byzantine school. On the dome, covered by red tiles towards the sea and by lead plates towards the east, stands a gilded copper statue depicting St. John (1395, the year of the end of the work).
Unique acoustics and structure
Extraordinary acoustics: The roofing system consists of a double dome, an inner truncated pyramid dome and an outer hemispherical dome. This particular architectural structure allows for exceptional acoustics, making it a true ‘musical instrument’. The personnel on duty, every 30 minutes, give the public a brief demonstration, intoning a few notes and leaving the rest to the magical reverberation produced in the majestic cylinder of the Baptistery.