Milan Cathedral, the Duomo di Milano, was begun in 1386 under Gian Galeazzo Visconti, who needed a public win after the brutal rule of his predecessor Bernabò Visconti and whose family had moved its court to Pavia. The cathedral holds 40,000 people, has the highest completed Gothic vaults of any church, and is faced in Candoglia marble. When Visconti tried to make it his family mausoleum, the Fabbrica del Duomo refused, and he built the Certosa di Pavia instead. He pushed for French Rayonnant Gothic over local Lombard brick, and in 1399 the Parisian architect Jean Mignot declared the work in peril of ruin and done without science. He was wrong, but the insult drove Lombard engineers to improve their geometry and hoisting.

After Visconti died in 1402 the project stalled for long stretches. Leonardo da Vinci submitted and then withdrew a wooden model in the 1488 dome competition, and Archbishop Carlo Borromeo and engineer Pellegrino Pellegrini purged noble tombs and pushed a Roman Renaissance facade that later architects fought to reverse. In 1805 Napoleon Bonaparte, set to be crowned King of Italy there, ordered the facade finished and promised French reimbursement that never came, so the Fabbrica borrowed and sold assets to finish in seven years. The final bronze door was inaugurated in January 1965, and the Fabbrica still quarries marble to replace stone dissolved by smog.

• The gilded Madonnina went atop the 100 meter spire in 1762, and locals call a day fair only when they can see her through the fog
• Marco d’Agrate’s 1562 statue of Saint Bartholomew drapes his own flayed skin over his shoulder
• The largest organ in Italy, with five manuals and 225 ranks, was commissioned under Benito Mussolini
• A 1786 meridian line from the Brera Observatory triggered a relay that ended with a castle cannon marking solar noon for the city
• A 2012 adopt a spire campaign offered donors of 100,000 euros a plaque on one of 135 spires