Built between 1059 and 1128, this octagonal building is the spiritual heart of Florence. Every child born in Florence was baptized inside its great stone font. The two enormous gilt-bronze doors on the eastern front were christened the "Gates of Paradise" by Michelangelo. It took Lorenzo Ghiberti more than 20 years to complete this masterpiece. The interior is decorated with a shimmering gold mosaic and features the tomb of the pirate pope, Baldassare Cossa, made by Donatello and paid for by the Medici family.