Louis Vuitton Foundation

Listen for a moment. Beneath the traffic noise, there is the sound of water. It runs over a wide cascade of steps below the building and catches the light. Above you, huge curved panels of glass lean out against the sky, like sails filled with wind. The ground here is wooded parkland, and the air smells of leaves and damp earth. It is a strange and memorable first sight. A ship of glass seems to have come to rest at the edge of a forest.

You are standing at the Louis Vuitton Foundation, a museum and cultural centre for contemporary art. It sits in the Bois de Boulogne, the great wooded park on the western edge of Paris. Right beside it is the Jardin d'Acclimatation, an old amusement garden that has entertained Parisian children since the nineteenth century. So this modern building has very traditional neighbours. Families with prams walk past people heading to see challenging new art, and the two worlds share the same paths.

The foundation was commissioned by Bernard Arnault. He leads LVMH, the luxury group that owns Louis Vuitton and many other fashion and drinks houses. He chose the Canadian-American architect Frank Gehry, who is famous for the titanium curves of the Guggenheim Museum in Bilbao, in northern Spain. The building opened to the public in October 2014. From the start, it was meant to be more than a corporate showcase. It was meant to be a new landmark for the city, set where few people expected one.

Here is the first thing most visitors miss. What you see is really two buildings, one inside the other. At the core is a cluster of white, block-like volumes, which Gehry's team called the iceberg. These hold the galleries. Wrapped around them are the twelve glass sails. The sails do not enclose rooms. They float outside, held up by a frame of wood and steel. Walk around slowly, and you can see the white iceberg through the gaps.

Gehry has spoken about his inspiration. He looked at the glass palaces and garden greenhouses of nineteenth-century Paris, including the great glass roof of the Grand Palais. In a park full of old conservatories and pavilions, he wanted a building of glass and light that belonged to that tradition. But he wanted it to look as if it was moving. The result is a structure that feels light and unsettled, even though it is enormous and very heavy.

The engineering behind that lightness was a huge task. The glass sails are made of about 3,600 individual panels, and almost every one is curved in its own unique way. The iceberg is covered in around 19,000 panels of a special fibre-reinforced concrete, a material that is strong but can be shaped thinly. Designing all of these by hand would have been impossible. The team used advanced aircraft-industry software to model each piece before it was made.

Now look at the water. The building sits above a long, shallow basin, and the water drops down a wide stepped cascade. This was a careful choice. The water reflects the sails, so the whole structure seems to rise from it. On a calm day, you see a second, upside-down building in the surface. When the wind moves, the reflection breaks apart into shivering pieces of white and blue. Stand by the edge for a minute and watch it change.

Here is the second surprise. Go down to the lower level, beside the cascade, and look for a passage called the Grotto. Inside is a work by the Danish-Icelandic artist Olafur Eliasson. It is a long row of tall columns, lit with warm yellow light and reflected in mirrors and water. The space seems to go on forever. Many visitors walk past the entrance without noticing it, because it sits below the main galleries. It is quiet down there, and the colour feels almost like sunlight underground.

Inside the iceberg, there are eleven galleries of very different sizes and heights. Some are tall and white, with light falling from above. Others are smaller and more private. There is also an auditorium, used for concerts, talks and performances. The foundation holds a permanent collection of modern and contemporary art, but its rhythm is set by large temporary exhibitions. Some of these have brought famous collections to Paris and drawn very large crowds.

The building itself has also become a canvas. In 2016, the French artist Daniel Buren covered the glass sails with coloured filters in blue, red, yellow and green. For months, the white ship became a moving pattern of colour, and the coloured light fell onto the terraces and the visitors below. It showed how the glass works almost like a screen. The architecture is not finished when the builders leave. Artists and light keep changing it.

If you go inside, do not stop at the galleries. Climb up to the roof terraces. These open-air decks sit between the curves of the sails, and the angles of glass frame the views in unexpected ways. To one side, you look across the treetops of the Bois de Boulogne. In the distance, you can pick out the towers of La Défense, the business district to the west. On a clear day, you may also catch the top of the Eiffel Tower rising above the trees.

Up there, you also understand the building best. You can see how the timber beams meet the steel joints, and how each glass panel overlaps the next, like scales. You can touch the wood and feel the rough grain. The scale is large, but the details are careful and handmade in feeling. People often say the building looks different from every side. From the terraces, you see that this is true, because no two views are ever the same.

Before you leave, walk once more around the outside. Notice how the light moves across the glass as the clouds pass. Listen again for the water on the steps, and the voices of children from the garden next door. This is a place where a forest, a playground and a modern art museum all meet. As you walk back along the park paths, turn around one last time. Through the trees, the white sails will still be there, catching the sky.