Skopje, the city the world rebuilt.

01 A city with an exact time

On the facade of the old railway station there is a stone clock stopped at 5:17. It is not a monument added later: it is the clock that stopped that July morning in 1963, when a magnitude 6.9 earthquake shook the city for twenty seconds. The building was sheared in half and left that way. Since 1970 it has housed the city museum.

The figures explain why the city could not simply be repaired. Some 1,070 people died and more than four thousand were injured. Around 15,800 buildings, homes and public facilities alike, were destroyed, and another 28,000 damaged. Two hundred thousand people were left without a home in a city of roughly two hundred thousand inhabitants. This was not a disaster you fix building by building.

02 The plan was signed by someone ten thousand kilometres away

What happened next is what makes this city singular. The rebuild became an international operation coordinated by the United Nations, with aid arriving from more than eighty countries and overall direction in the hands of the Polish planner Adolf Ciborowski. It was the first time the UN Special Fund backed the full reconstruction of a city.

In January 1965 a limited competition was called for the new centre: four foreign practices and four Yugoslav ones. It was won by the Japanese architect Kenzo Tange, who took sixty per cent of the first prize and developed the proposal alongside local architects. The plan was formally approved on 16 November of that same year. Its idea was to reorient Skopje as a linear city running west to east along the Vardar, with wide boulevards that would double as evacuation routes.

The most recognisable piece of that plan is the Gradski Zid, the «city wall»: a row of long eight-storey blocks ringing the centre like a residential rampart, built between 1967 and 1976. Its stair and lift towers project from the volume like buttresses. It is planning shaped like defence, though what it defends is not an enemy but an idea: that the centre should have a legible edge.

03 Concrete as a shared language

Walking central Skopje means working through a catalogue of 1970s exposed concrete, and it should be said that it is not a comfortable catalogue. The Post Office and Telecommunications Centre, both by Janko Konstantinov, are the largest piece: the technical centre went up between 1972 and 1974 as an almost fortress-like structure served by external cylinders, and the postal hall, finished between 1979 and 1981, is topped by concrete ribs that bloom over the dome, halfway between archaic and futuristic.

The campus of Ss. Cyril and Methodius University was designed by the Slovenian architect Marko Mušič, who won an open competition and built it between 1970 and 1974 in béton brut. And between those major pieces sit dozens of office and housing blocks from the same decade, with their cantilevers, their vertical fins and, today, their air-conditioning units bolted to the facade. That detail matters: modern heritage here is not put behind glass, it is inhabited and a little tired.

04 What the earthquake left standing

Here is the tension that gives the place its depth. On the northern bank of the Vardar the old bazaar survived, a set of Ottoman-era trading streets laid out in the fifteenth century, with its workshops, its inns and its baths. It is a small-grained fabric —single-bay shops, low roofs, stone lanes— that withstood what the centre did not.

The result is a city of two scales that touch without mixing. You cross the stone bridge, also fifteenth-century, and within a hundred metres you go from two-metre lanes to six-lane boulevards. It is not a transition between neighbourhoods: it is a transition between centuries and between ways of building, and it happens on foot, in five minutes.

It should also be said that the reconstruction did not deliver on all of its promise. Tange's plan was only partly built, and much of what did go up has been waiting decades for maintenance that never arrives. Skopje is not a city where modern concrete is displayed with pride; it is one where it holds on as best it can.

05 What Skopje leaves you

What you take away is not a handsome skyline. It is the strange awareness of walking through a city that exists because a great many people who did not live here decided it should. A Japanese plan, a Polish director, money and materials from more than eighty countries, and a crowd of young architects handed an entire capital to think about, all at once.

That is the question Skopje leaves open, and it has no easy answer: what happens when a city is rebuilt quickly and from outside. You can see the price here —a centre that aged badly, a plan half-delivered— and also the achievement, which is enormous: within a few years there was a city again. Few places let you look at both at once, from the same pavement.