The famous art historian (or gossip) Giorgio Vasari (1511-1574) designed a Last Judgement fresco 1572-9 to cover the 3,600 square meters (38,750 sq ft) ceiling of the dome.
The painting is easy to enjoy. The main scene visible from the nave is the Last Judgement. At the opposite end is the three-faced devil stuffing humans into his three mouths. The main scenes in rings from the lantern down: the 24 Elders, Choirs of Angels, Christ, Mary and Saints, the Virtues, and finally the Capital Sins and Hell.