The octagonal Baptistery on the Piazza del Duomo is a transitional building between Romanesque and Gothic, built in pink Verona marble and largely the work of Benedetto Antelami from the 1190s onward. Outside, three carved portals show scenes from the life of John the Baptist and a magnificent Christ in Majesty; inside, an early 13th-century fresco cycle around the dome depicts the labours of the months, the apostles, and the prophets.
The pink stone glows in late afternoon sun. Climb to the upper galleries for a close look at the painted vault. Tickets for the baptistery also give access to the diocesan museum next door, which holds the cathedral's silver, vestments, and a Roman mosaic.