A fine example of 11th century Romanesque architecture, its layout is octagonal and it has a diameter of 26 meters (ca.). Its roofIs pyraimd-shaped and topped by a lantern with columns; it is also covered in white and green marble. It was the city’s cathedral untll 1198 and is dedicated to St. John the Baptist. Many illustrious men of Florence, including Dante, were baptized here The interior consists in a single room embellished with marble and Byzantinestyle mosaics on the vault. The images represent the Heavenly Hierarchies, Stories o/the Genesis, Stories of Mary and Jesus, Stories of St. John the Baptist, and the Last Judgement. The marble baptismal font (1371) attributed to the Pisan school is rather interesting. The Tomb of the anti-Pope John XXIII by Donatello and Michelozzo is also lovely.
You’ll be able to see the remains (walls and mosaic floor) of a Roman house through a grid on the floor. The Baptistery has 3 bronze Doors: the one to the south is by A Pisano (1336) and is divided into 28 tiles with stories of St. John the Baptist and the Cardinal and Theological Virtues. The other doors (1403-1452) are both by Ghiberti. The one on the north side, also called the «Cross Door,” depicts 20 scenes from the New Testament and 8 tiles wìth the Fathers of the Church and the Evangelists.
Michelangelo defined the east door as the Gate of Heaven Ghiberti used perspective for the 10 gilt bronze tiles obtained with the “schiacciato” technique (flattened relief). The bas-reliefs depict Stories from the Old Testament enclosed in a frame with 24 niches representing biblical figures and 24 heads of artists including Ghiberti’s own self-portrait (he is bald and is the fourth from the top on the right side of the left panel).