Grande Arche de la Défense

Stand still for a moment and listen. The wind comes first. It runs across the wide stone plaza, pulls at your coat, and hums faintly through the gap ahead of you. Underfoot the paving is hard and pale, and when the sun is out it throws light straight back into your eyes. Ahead rises an enormous white frame, open in the middle like a window with no glass. You are standing in front of the Grande Arche, at the western edge of the business district of La Défense, just beside Nanterre.

At first glance it looks simple. It is a hollow cube, roughly as wide as it is tall and as deep as it is wide, and each side runs to more than one hundred metres. But the simplicity is a trick of scale. The two vertical sides are full office buildings. The roof is a bridge, several storeys thick, joining them at the top. What looks like a picture frame is really a structure people work inside every day.

Now turn around. Look back the way you came, toward Paris. On a clear day you may be able to trace a long, straight line through the city. It runs past the towers of La Défense, down the Avenue de la Grande Armée, through the Arc de Triomphe, along the Champs-Élysées, and on toward the Louvre. The French call this line the historic axis. For centuries kings, emperors and presidents extended it, each adding a monument. The Grande Arche was built to close it, at least for now.

That idea of a closing point shaped the whole project. In the early 1980s President François Mitterrand launched a set of major building works in and around Paris, often called the Grands Projets. They included the glass pyramid at the Louvre and a new opera house at the Bastille. For the far end of the axis, an international competition was held. The winner was not a famous name at all. He was a Danish architect, Johan Otto von Spreckelsen, little known outside his own country.

Spreckelsen had built mostly churches and modest houses in Denmark. His design for Paris was bold in its restraint. He imagined a modern triumphal arch, but one dedicated to humanity and ideas rather than to military victory. It was sometimes described as a window open onto the world. Some writers also describe the form as a kind of three-dimensional shadow of a four-dimensional cube, a mathematical shape called a hypercube. Whether or not you see that, the geometry is meant to feel pure and calm.

Here is the first detail most visitors miss. The arch does not sit squarely on the historic axis. It is turned slightly, by a few degrees, so it does not line up exactly with the Arc de Triomphe. Stand in the centre of the plaza and compare the angle of the arch with the line of the towers behind you. You may notice the twist. It is usually explained by what lies underground. Beneath your feet run railway lines, metro tunnels and roads, and the foundations had to find space between them.

The story behind the building has a sad turn. The project was large, political and complicated, and Spreckelsen did not stay to finish it. He stepped away during construction, and he died before the arch was complete. The French architect Paul Andreu, known for his airport designs, took over and carried the work through. The structural engineering was led by the Danish engineer Erik Reitzel, who had worked with Spreckelsen from the start.

The arch was inaugurated in July 1989. That date was chosen with care. It marked two hundred years since the French Revolution of 1789. In the same month, leaders of the world's largest economies met here for their annual summit. So the building opened under the eyes of presidents and prime ministers, as a symbol of a modern France looking outward.

Look closely at the surface. The outer faces are clad in white marble from Carrara in Italy, the same region that supplied stone to Michelangelo. Between the marble panels sit large areas of glass and granite. From a distance it reads as a smooth white block. Up close you see the grid of panels and joints. You may also see slight differences in tone where stone has been cleaned or replaced. Marble on this scale needs care, and the arch has gone through long periods of repair and renovation.

Now step under the arch and look up. Hanging inside the opening is a light, tent-like canopy of fabric and cables. It is often called the Cloud. Its job is partly practical. It softens the wind that rushes through the gap and gives a sense of shelter. It also breaks the hard geometry with something soft and irregular. On a grey day it almost disappears into the sky. On a bright day it throws a pale, filtered shadow across the steps.

Those steps are the second surprise. The wide staircase in front of the arch is one of the great public seats of the district. At lunchtime office workers sit here with sandwiches and coffee. Teenagers meet friends. Skateboarders try tricks on the plaza below. It is a monument, but people treat it like a front porch. Take a seat yourself and watch how the space fills and empties with the rhythm of the working day.

It is often said that a cathedral like Notre-Dame de Paris could fit inside the opening of the arch, spire and all. Treat that as a popular image rather than a precise measurement. But it gives you a sense of the void in front of you. The space between the two sides is a room with no walls, and the sky is its ceiling. The building is famous less for what it contains than for the emptiness it frames.

Inside, most of the arch is ordinary office space, used largely by government departments and private companies. At times the roof has opened to visitors, with exhibitions and views back along the axis toward Paris. Access has changed over the years, so it is worth checking the current situation before you plan to go up. Even from the ground, though, the arch works as a viewpoint. It turns your eye back toward the city it was built to answer.

Before you leave, stand once more in the centre of the plaza. Let the wind find you again. Look through the frame to the west, where the axis runs on beyond the business district. Then turn and look east, down that long straight line toward the Louvre. Behind you is a white square in the sky, built for an anniversary, finished by other hands, and slightly turned on its foundations. As you walk away, glance back once. The window stays open.