Baptistery of San Giovanni, Medieval baptistery near Cathedral of Santa Maria Assunta in Volterra, Italy

The Baptistery of San Giovanni is an octagonal stone building from the second half of the 13th century, standing in front of Volterra's Duomo. Its facade facing the cathedral is clad in horizontal bands of white and green marble, with a Romanesque portal attributed to sculptors linked to Nicola Pisano. Inside, six niches surround the space beneath a dome, with a 1759 baptismal basin by Giovanni Vaccà at the centre.

The octagonal baptistery was built in the second half of the 13th century, supposedly on the site of a 7th-century baptistery that itself stood over a Roman temple of Sun worship. Its Romanesque portal, facing the cathedral, is attributed to sculptors dependent on Nicola Pisano. The interior was later enriched with a 1471 ciborium by Mino da Fiesole, a 1502 font by Andrea Sansovino, and a 1759 baptismal font by Giovanni Vaccà.

The name recalls John the Baptist, to whom the baptistery is dedicated. The central 1759 basin by Giovanni Vaccà is crowned by Giovanni Antonio Cybei's 1771 statue of the Baptist, and the 1502 font by Andrea Sansovino stands beside the altar. The painting above the altar, Niccolò Circignani's Ascension, lost its upper part in World War II bombing.

The building sits beside the Cathedral and is easy to reach on foot while exploring the old town. It is helpful to check opening times before visiting, as they change between winter and summer seasons.

An ancient Roman sarcophagus has been repurposed as a holy water container inside the baptistery. This unusual reuse connects the pagan and Christian periods of the site in a subtle way that many visitors do not immediately notice.