Naqsh-E Jahan Square

Go into the small mosque on the east side of the square in the middle of the day and look straight up. There is an opening at the crown of the dome, and the light coming through it lands as a narrow shaft on the inner surface, where it catches the tilework fanning out from the central medallion. For part of the day the effect resolves into something specific: a peacock, tail spread, the rings at the end of the feathers supplied by the pattern itself.

Nobody can say for certain whether it was calculated. The mosque was built for a court that employed the best geometers in Iran, which argues one way, and light does this kind of thing by accident all the time, which argues the other. Either way people have been walking in at the right hour and looking up for four hundred years.

A Capital Moved On Purpose

In 1598 Shah Abbas I moved the Safavid capital south from Qazvin to Isfahan. The reasoning was military and commercial, but Abbas did not simply relocate; he had the centre of the new capital drawn from scratch. South of the existing old square, surveyors laid out a rectangle over 500 metres long and about 160 wide and wrapped all four sides in a two-storey arcade of shops, every bay identical to the next.

The monotony is the point. The arcade runs the whole way round in one rhythm, and it breaks in exactly four places: a gate in the middle of each side. North to the bazaar, south to the great mosque, east to the small mosque, west to the palace. Four institutions that had spent centuries jostling each other were put into a single sentence, evenly spaced.

And in the middle, deliberately, nothing. The empty rectangle was a market on some days, a parade ground on others, and a polo field regularly. The stone goalposts are still standing at either end of the square, about waist height, and most people walk past them without a glance.

The Balcony

The palace on the west side, Ali Qapu, is six storeys high, and its columned porch hangs directly over the square. That balcony did double duty: the ruler received ambassadors there and watched the polo, the parades and the punishments from it, and the whole square watched him do it.

Higher up in the same building is something else entirely. One room has its walls and ceiling cut into plaster panels shaped like bottles and jars, silhouette after silhouette carved right through the surface. They are not decoration. They break up reflected sound. It is a music room, and it is four centuries old.

The Building That Turns

The great mosque on the south side had a geometry problem. The square is not aligned with Mecca; the angle between them is close to forty-five degrees. The architect neither hid this nor let it distort the square. The mosque's portal sits perfectly square to the arcade, and then, once you are through it and along a short passage, the building quietly rotates and the courtyard faces where it should. From outside nothing is out of true. From inside you have changed direction without noticing.

Under the main dome there is a dark stone set into the floor. Stand on it and speak and the sound comes back at you several times over, a by-product of the dome being built as two shells with a gap between them. Whether that was designed or inherited from the geometry is argued about. Guides clap on it every day, and it works every day.

The Archer On The Gate

The bazaar gate at the north end carries a piece of tilework that has nothing to do with religion: a centaur-like archer, bow drawn, shooting backwards at a tail that ends in a dragon's head. It is the zodiac sign associated with Isfahan, put on the front door of the commercial half of the square. Above and around it there were once painted scenes of the shah's campaigns, of which only traces survive. The square was never purely a religious space, and its main entrance says so before you are through it.

What It Survived

The Safavid dynasty collapsed under siege in 1722 and Isfahan went into a long decline. The capital moved elsewhere, stretches of the arcade fell down, and parts of the open ground were built over or turned into gardens. The square was progressively cleared and restored during the twentieth century. Its official name changed after 1979, though plenty of people in the city still use the old one, which means something like the pattern of the world.

Now

It was among the first Iranian sites inscribed on the World Heritage list, in 1979. In the evenings families spread carpets on the grass in the middle, and the shops in the arcade are still shops.

The threat comes from underneath. Isfahan's river runs dry for much of the year, and the groundwater pumped for agriculture and the city is letting the ground settle. Subsidence in parts of the city is measured in centimetres a year, and in historic buildings it reads as cracks. For brick domes that have stood for four hundred years, the test now is not the weather above them but the water being taken out below.