One of the most prominent buildings in the city and the region, representing the transition from late Romanesque to the early Gothic style. It is constructed from pink marble and bronze, with construction beginning in 1196 and completed in 1307.

The decorative work was entrusted to Benedetto Antelami, and the building is designed in an octagonal shape, symbolizing eternity in Christianity. The Romanesque style is particularly striking on the exterior. The building has three entrances and rises five stories high, above the arches of the entrances, creating an impressive vertical structure.

The northern doors face the Duomo square.

The western doors are decorated with scenes of the Last Judgment.

The southern doors are known as the Gates of Life.

Around the exterior, carved animal figures resemble a parade in a zoo.

Inside, the baptistery is captivating with its 16-sided structure, decorated with paintings of the seasons, zodiac signs, and the months of the year around the double-walled baptismal font. The dome is also adorned with stunning paintings of saints, Jerusalem, prophets, and various symbols of life.