CATHEDRAL, Interior Naves
The interior of the Cathedral is so big, you'll find yourself standing there with your mouth hanging wide open. This effect of vast emptiness is produced by the amplitude of arches supported by only six large octagonal pillars.
Gradually lowering your gaze, you can admire a gallery halfway up that runs along the entire extent of the Cathedral, the stained glass windows painted in the 1400s, and at your feet the austere 16th-century pavement in colored marble.
When Brunelleschi's dome was completed, the Cathedral began to be seen not only as the Florentines' main place for worship, but even more so as the proud symbol of the city's identity. In fact, you may notice that there are few altars along the walls, while the figures celebrated are those who have made Florence what it is today: musicians, artists, leaders, and intellectuals. On the right wall you can see the busts of Brunelleschi, Giotto, and the philosopher Marsilio Ficino; on the other side you can see the two most important works of art in the Cathedral: two very important frescoes that copy two commemorative monuments. These are the symbolic graves of two great leaders who commanded Florentine troops in battles, and are both depicted on horseback. To the left is the Equestrian Statue of Niccolò da Tolentino made by Andrea del Castagno, and on the right is the statue of Englishman John Hawkwood (who in Florence was called "Giovanni Acuto") made by Paolo Uccello.
Continuing on the same side, you can admire an "altarpiece" dedicated to Dante Alighieri, whose Divine Comedy cast light on Florence. The city is depicted on the right: behind the walls you can easily recognize the dome of the Cathedral, the Tower of Palazzo Vecchio, etc., on the other side you can see the terraced mountain of Purgatory and the door that leads to Hell, and at the top the skies of Paradise.
The painting was created by a pupil of Fra Angelico to mark the bicentenary of the great poet's birth.
Among many other works of art, I'd also like to point out the great 15th-century clock inside the façade. The dial is not divided into twelve sections, but into 24. The four circles at the corners feature four bearded prophets with intensely accentuated expressions: they were painted by Paolo Uccello.
FUN FACT: a bull's head stands on the left side of the Cathedral. According to popular rumor, a carpenter who worked on the building had had an affair with the wife of a nearby baker. The bull was put there to mock the cuckolded husband, and in a position where he couldn't miss seeing it.