How Milan was built and evolved over time

Flat ground, built over repeatedly

Milan's building history is unusual among Italian cities because nothing about the site constrained it. There is no hill to terrace, no river to bridge, no lagoon to pile into. The city could expand in any direction and did, which means its form is made entirely of human decisions — and because each era could build over the last rather than around it, the layers are stacked rather than side by side.

The Roman grid and the concentric rings

A Roman rectilinear grid underlies the oldest core, and its lines still govern the streets immediately around the cathedral. Over it, Milan grew in rings: the medieval walls, then the far larger Spanish walls of the sixteenth century, which set the shape of the inner city for three hundred years. The walls are mostly gone, but the ring roads follow them, which is why central Milan reads as a set of circles on a map and why its gates — Porta Venezia, Porta Romana, Porta Garibaldi — are traffic junctions with names older than the roads.

The cathedral, and six centuries of one building

The Duomo is the city's longest construction project and its most instructive. Begun in 1386 and formally completed in 1965, it is 158.6 metres long, 92 metres wide and 108 metres high, with five naves carried on forty pillars. It was built throughout in Candoglia marble, from quarries Gian Galeazzo Visconti donated in perpetuity to the cathedral chapter — which is why a building that took 579 years is faced in a single consistent stone.

Its history is a record of who held the city. Leonardo da Vinci and Donato Bramante submitted competing designs for the crossing cupola in 1488; the facade was finally finished after Napoleon ordered it done in 1805; and the Madonnina was raised on the main spire in 1762, at 108.5 metres, to Giuseppe Perego's design. The roof terraces are open to walk on, which makes it one of the few cathedrals where the structure can be examined from above.

The canals, and their disappearance

The Navigli were the city's answer to having no navigable river: a canal network, dating back as far as the Middle Ages, that linked Milan to the Ticino and the Adda and so to the Po. They carried goods into the heart of the city, including the cathedral's marble. Most of the urban network is now invisible — the urban section of the Naviglio Martesana was covered over at the beginning of the 1930s, together with the entire Inner Ring — and what survives is the southern stretch around the Darsena, which is why the Navigli district feels like a fragment rather than a system.

Iron, glass and the nineteenth century

The Galleria Vittorio Emanuele II is the clearest statement of unified Italy's confidence in its new economic capital. Giuseppe Mengoni designed it in 1861 and it was built between 1865 and 1877: four barrel vaults around 14.5 metres wide and 8.5 metres high, meeting under a dome of roughly 37.5 metres internal diameter and 17.10 metres high, with ironwork from the Atelier Henry Joret and ribbed glass from Saint-Gobain. It is Italy's oldest shopping arcade still in use, and the mosaics in the central octagon carry the arms of the Kingdom's three capitals — Turin, Florence and Rome — alongside Milan's own.

Bombing, the boom, and the towers

Allied bombing in 1943–1945 destroyed much of the industrial city and damaged the centre, and the post-war boom filled the cleared ground fast. That is the reason central Milan mixes intact palazzi with 1950s and 1960s construction on the same street rather than in separate districts, and it is also when Milan produced its most distinctive modern buildings. Most recently the Expo of 2015 drove the Porta Nuova and CityLife clusters and the reopening of the Darsena, giving the city a high skyline for the first time.