Florence's Duomo, or cathedral, completed in 1327, is the fourth largest church in the world, and its domed roof is symbolic of the meeting of Renaissance craft and culture. Engineered by the architect and sculptor Filippo Brunelleschi, the dome was one of the greatest achievements of the Italian Renaissance.

Its octagonal form has a diameter of 153 feet at the base, and was completed in 1436; it is possible to climb to the top of the dome for magnificent views over the city. The vast interior boasts sculptures by Renaissance masters such as Paolo Uccello, Andrea del Castagno, Giorgio Vasari and Federico Zuccari.

The Duomo stands on the remains of an older cathedral, which can be seen in the archaeological area revealed beneath the floor. The bronze doors of the baptistry, the oldest building in Florence, were cast by Lorenzo Ghiberti in the early part of the 15th century and were described by Michelangelo as fit to be the gates to paradise. The nearby bell tower is decorated inside with frescoes by Giotto and Donatello, among others.