Cupola del Brunelleschi

The dome that solved an impossible problem still dominates Florence. Built between 1420 and 1436 by Filippo Brunelleschi without traditional centring, the double-shell vault of Santa Maria del Fiore can be climbed: 463 steps lead between its walls to the lantern, past Vasari's vast Last Judgment below.

Why it matters

Brunelleschi's dome is the symbol of Florence and, in the Opera's own presentation, a masterpiece of art and of Renaissance humanism. Measuring 45.5 metres in diameter and rising more than 116 metres in total height, it is the largest masonry vault ever built, and it was raised between 1420 and 1436 from the project Brunelleschi presented in the competition launched by the cathedral's Opera in 1418. Its engineering secret, a self-supporting double shell with the inner structure braced by ribs and bricks laid in a herringbone pattern, removed the need for the full wooden centering that earlier practice required. Climbing it is therefore not a viewpoint errand but a passage through the machine itself, between the two vaults that made the trick work.

What to notice

The ascent follows the space between the shells. You walk on passages built into the masonry, and the brickwork around you shows the herringbone course and the geometry of the eight ribs; keep an eye on the wall openings, which frame sudden views of the city and return you to darkness. Lower galleries also give close sight of the interior surface, where Giorgio Vasari and Federico Zuccari painted the enormous Last Judgment between 1572 and 1579, a cycle partly inspired by the baptistery's mosaics. At the top the stair arrives at the base of the lantern, the highest panoramic point above Florence, where the marble drum and the view over rooftops and hills reward the climb. The lantern itself, a white marble tower some 21 metres high, was built after Brunelleschi's death in 1446 to his own design, crowned by the gilt copper sphere and cross attributed to Andrea del Verrocchio.

Context and history

When the cathedral's eastern drum was completed, its width made a traditional domed roof unbuildable with known means. The Opera's 1418 competition produced Brunelleschi's proposal, and construction ran from 1420 to the vault's closure in 1436, the year Pope Eugene IV consecrated the cathedral. The innovation was structural: an inner shell more than two metres thick of light bricks set herringbone acts as the self-supporting element, while the outer shell, covered in terracotta tiles and marked by eight white marble ribs, serves as weatherproof covering and profile. Work stopped for good in 1446 with the architect's death, and the lantern followed on his design. The dome's interior waited longer for decoration until the Vasari-Zuccari Judgment of 1572–1579. A major restoration of those frescoes ran from 1978 to 1994. The Opera describes the vault as the largest masonry dome in the world, a superlative in this case grounded in the fabric itself.