Notre-Dame du Haut

Listen first. Up here on the hill, the wind moves through the trees and across the open grass. The path climbs gently, and then the chapel appears. It is a white, curving mass under a heavy dark roof that seems to float. The walls look soft, almost hand-shaped. The roof bulges like a sail filled with wind. Before you know any history at all, the building makes you slow down and look again.

You are standing on the hill of Bourlémont, above the small town of Ronchamp, in eastern France. This hilltop has drawn pilgrims for centuries. People climbed here to honour the Virgin Mary, and the name of the chapel means Our Lady of the Heights. The place was sacred long before the building in front of you existed. The architecture is new. The devotion is old.

The chapel you see replaced an earlier one. During the Second World War, fighting reached this region, and the previous chapel was badly damaged in 1944. After the war, the church needed a new building for the pilgrims. The commission went to Le Corbusier, the Swiss-born architect who was famous for straight lines, flat roofs and buildings he called machines for living. Many people expected a cool, rational box. They got something very different.

The chapel was completed and consecrated in 1955. Critics were surprised, and some were shocked. Here was the great champion of modern order, designing a building with almost no right angles. The walls lean. The roof curves. The windows are scattered like stars. For many architects, Ronchamp marked a turning point. It showed that modern architecture could be emotional, sculptural and deeply spiritual, not only practical.

Look up at the roof. It is dark, heavy concrete, and it curls upward at its edges. Le Corbusier said that a crab shell gave him the idea. A shell is thin but strong, because of its curve. The roof works in a similar way. It is actually two thin concrete layers with a hollow space between them. So the roof looks massive, but it is lighter than it appears.

Now here is a detail many visitors miss. The roof does not sit directly on top of the walls. Between the wall and the roof there is a narrow gap. From inside, you will see a thin line of daylight running along the top of the wall. It makes the heavy roof seem to hover. Small supports hidden in the walls hold the roof up. It is a quiet trick — and once you notice it, you cannot stop seeing it.

Walk around to the south wall, the one facing the valley. It is very thick, and it leans inward. Deep, irregular openings are cut through it at different angles. Some are tiny, some are large. Many are filled with clear or coloured glass, and Le Corbusier painted words and simple images on several panes. The walls were built partly with stone from the ruined chapel, then covered with sprayed concrete and whitewash. The old chapel lives on inside the new one.

Step inside, and your eyes need a moment. The interior is quiet and dim. The floor slopes gently downhill, following the shape of the land. Light enters through the deep windows of the south wall and spreads across the white surfaces in soft shafts of colour. Above you, the line of light under the roof glows. It does not feel like a large hall. It feels more like a cave shaped by hand.

The chapel has three towers, and each one is a kind of light catcher. They rise above the roof and bend their openings toward different directions of the sky. Daylight falls down through them into small side chapels below. Because the towers face different ways, the light inside changes through the day. A visit in the morning and a visit in late afternoon can feel like two different buildings.

On the east side, the chapel opens to the outdoors. There is an outdoor altar and a pulpit under the overhanging roof. On major pilgrimage days, large crowds gather on the grass, and the hillside itself becomes the nave, the main space where the congregation stands. Set into the east wall is a small statue of the Virgin in a glass case. It can turn to face the people inside, or the crowds outside.

Now look for the rain. On the west side, the roof channels water into a large spout that sticks out like a gargoyle, a carved water spout found on old cathedrals. When it rains, water pours from it into a concrete basin below. Inside the basin stand several geometric concrete shapes. Even the drainage became sculpture here. Le Corbusier also designed small buildings on the site, including a pilgrims' house, and a stepped stone pyramid that serves as a memorial for peace.

The site kept changing after Le Corbusier. In the early 2010s, a new entrance building and a small convent were added by the Italian architect Renzo Piano. He set them low into the slope, so they would not compete with the chapel. A community of nuns lives there today. In 2016, the chapel was listed by UNESCO, together with other works by Le Corbusier across several countries. It is still a working place of prayer, not only a monument.

Before you leave, stand back on the grass and look once more. Notice how the building changes as you walk around it. From one side it looks like a ship. From another, a tent, a shell, a pair of hands held together. Feel the wind on this open hill. Listen to the quiet. And as you walk down the path, look back one last time at that dark roof, floating above its white walls.