Duomo di Milano
The vast Gothic cathedral that took roughly six centuries to finish, faced in pink-white Candoglia marble. The detail that explains the city: the cathedral works has held quarrying rights at Candoglia since the fourteenth century and still does, so the building is repaired with stone from the same seam it was built from.
Galleria Vittorio Emanuele II
The glass-roofed arcade of 1865 to 1877 linking the cathedral square to La Scala, and arguably the ancestor of every shopping mall since. In the central octagon, look down: visitors grind their heel into the testicles of a mosaic bull for luck, wearing a hole in the floor that has to be repeatedly repaired. The bull is Turin's coat of arms, not Milan's.
Santa Maria delle Grazie and the Last Supper
The Dominican refectory holding Leonardo's mural, painted in the 1490s in an experimental technique that began deteriorating almost immediately. On 15 August 1943 Allied bombing destroyed much of the building. The wall carrying the painting had been sandbagged and survived a high-explosive bomb that landed around eighty feet away.
The Navigli
What remains of the canal network, now two surviving stretches lined with bars. Most of the system was covered over in the twentieth century, so the water you see is a fragment. Leonardo worked on this network for Ludovico Sforza, designing lock systems to handle the altitude difference between Milan and the lakes.
Castello Sforzesco
The brick fortress of the dukes who ran Milan through its richest period, and the reason Leonardo was in the city at all. He arrived in 1482 at Ludovico Sforza's invitation, pitching himself primarily as a military and hydraulic engineer. The castle holds his ceiling fresco in the Sala delle Asse and Michelangelo's unfinished final sculpture.
Teatro alla Scala
The opera house of 1778, built on the site of a demolished church that gave it its name. Its reputation rests less on the building than on its audience: the loggionisti in the upper gallery are famous for booing singers off the stage, and a debut here is treated as a genuine trial rather than a formality.
San Maurizio al Monastero Maggiore
A sixteenth-century church covered wall to ceiling in roughly 450 frescoes, by Bernardino Luini among others, and locally called the Sistine Chapel of Milan. It is free and usually close to empty. It sits a few minutes from the Duomo, where people queue for hours, which is the most useful thing to know about it.
Cimitero Monumentale
A working cemetery laid out in 1866 where Milan's industrial families competed through funerary sculpture, producing an open-air gallery of art nouveau and futurist monuments. It reads as a portrait of who had money and wanted it recorded. Entry is free and it is one of the least visited significant sites in the city.
Pinacoteca di Brera
The state art collection, assembled substantially from religious houses suppressed under Napoleonic rule, which is why so much of it is altarpieces removed from churches elsewhere in Lombardy. The gallery exists because of confiscation. That origin is not hidden, but it is rarely the first thing anyone tells you about it.