Introduction to the Baptistery of San Giovanni: The Baptistery of San Giovanni is located a few meters west of the Cathedral. It was built in the 7th century AD and was converted into the current octagonal marble Romanesque building between the 11th and 12th centuries. The building has a diameter of 27.5 meters, the interior is covered by a dome, and is about 31 meters high. Children in Florence were baptized here, including celebrities such as Dante and Machiavelli.