Battistero Lateranense

The Basilica di San Giovanni in Laterano's octagonal baptistery, built by Constantine in the 4th century, served as the prototype for later Christian churches and bell towers. Its plain brick exterior gives onto a richly decorated baroque interior centered on a baptisimal font surrounded by two towering tiers of columns, the lower order made up of eight colored porphyry columns, the upper order of white marble pillars. A further highlight is the Cappella di San Venanzio with a glittering Byzantine mosaic.