Overview
The Lateran Baptistery, also known as San Giovanni in Fonte, was built at the behest of Constantine in 315-324. It was Sixtus III who commissioned the construction of the atrium, while the doorway dates back to 1575, and other restorations were carried out in the 17th century. In the octagonal interior, there are two rows of porphyry columns with Corinthian capitals supporting the architrave surmounted by a tiburium. A circular enclosure protects a basalt urn used for baptisms by immersion. You can admire mosaics from the 7th century in the Chapel of San Venanzio and from the end of the 5th century in the chapels of Santo Rufina and San Giovanni Evangelista, the latter closed off by bronze gates dating to 1196.
