Louvre-Lens

Listen to your footsteps for a moment. The ground here is flat and quiet, a soft parkland of grass, birch trees and gravel paths. Ahead of you, long low buildings of glass and pale brushed aluminium sit almost flush with the earth. They do not tower. They reflect. On a grey northern morning, the metal walls take on the colour of the sky, and the trees around you appear in the facade like soft, blurred shadows.

This is the Louvre-Lens, a branch of the most visited museum in the world. It sits not in Paris but in a former coal-mining town in the far north of France. It opened to the public in December 2012. For many people, the choice of place was the surprise. Why bring paintings and sculptures from the Louvre to Lens? The answer lies under your feet, and in the landscape all around you.

For well over a century, this region was coal country. The mining basin of Nord-Pas-de-Calais fed the furnaces and factories of industrial France. The ground you are standing on was once a pithead, a working mine site with shafts, rail lines and spoil. The pit here closed around 1960. After that, the land lay empty for decades. The museum was built on that wasteland, as a deliberate act of renewal for a region hit hard by the end of mining.

That same year, 2012, UNESCO added the mining basin of Nord-Pas-de-Calais to its World Heritage List. The listing recognises the pit towers, the workers' housing, and the great black slag heaps that rise across the plain. On a clear day, look out toward the horizon. You may see the dark cones of these spoil heaps, called terrils in French. They are made from the waste rock of the mines. Today many are covered in grass and trees, and some are open to walkers.

Now, the building itself. It was designed by the Japanese architecture firm SANAA, led by Kazuyo Sejima and Ryue Nishizawa. Their work is known for lightness, thin lines and reflective surfaces. Here, they placed a chain of simple rectangular halls side by side, linked at their corners. The halls bend slightly to follow the shape of the old mine site. From above, the plan looks almost like a row of boxes gently pushed out of line.

Notice how little the building rises from the ground. There is no grand staircase, no monumental entrance, no dome. The architects wanted the museum to feel open and easy to enter, not like a palace. This matters in a town where many families had never set foot in a fine-art museum. The glass entrance hall at the centre is transparent on all sides. From inside, you look straight out to the park and the trees.

The heart of the museum is a single vast room called the Galerie du Temps, the Gallery of Time. It runs about one hundred and twenty metres long, with no internal walls to break it up. Here is the first thing many visitors miss: the floor is not perfectly flat. It follows the gentle slope of the land beneath it. As you walk through the gallery, you are moving very slightly uphill or downhill, following the old ground of the mine.

The idea of the Gallery of Time is simple and bold. Works from the Louvre's collections are laid out in one long timeline. You begin with the earliest civilisations, with objects from ancient Mesopotamia and Egypt. You walk forward through Greece and Rome, through the Middle Ages and the Renaissance, and on toward the nineteenth century. Instead of separate departments for painting, sculpture or archaeology, everything from one period stands together. A Roman marble may face a coin, a vase and a carved stone from the same age.

Look at the walls of the gallery. They are lined with polished aluminium, which catches the shapes of the visitors and the objects in soft reflections. Daylight enters through the glazed roof and is filtered so the room stays calm and even. Along one wall, the centuries are marked so you always know where you are in time. You can stand at one end and see, in a single glance, thousands of years of human making.

Here is a second surprise. In the opening years, one of the most famous paintings in France hung here: Eugène Delacroix's Liberty Leading the People, the image of a woman holding the French flag above the barricades. In early 2013, a visitor wrote on the canvas with a marker. The marks were on the surface and conservators were able to remove them. The painting later returned to Paris. The story is a reminder that the works shown here are the real originals, not copies.

The display in the Gallery of Time is not fixed. Works travel between Paris and Lens, so the selection changes over the years. Alongside the long gallery, the museum also stages temporary exhibitions in a separate hall, often built around a single theme, artist or civilisation. Because of this rotation, a visit here is rarely the same twice. Regular visitors from the region come back to see what has arrived since their last trip.

Step back outside and look at the park. The landscape was designed to carry traces of the mining past. Paths follow the lines of the old rail tracks that once carried coal away from the pit. The planting is gentle, with lawns, young woodland and open clearings. Families picnic here, runners pass, and children roll down the grassy slopes. The museum and its grounds were meant to belong to the town, not only to visiting art lovers.

Before you leave, stand for a moment and look at the building again. Watch how the aluminium walls hold the shapes of the trees and the clouds, how the glass lets you see straight through to the far side. Behind it lies a hall where four thousand years of art sit under one roof. Around it lies the ground where generations of miners once worked. As you walk away, listen to the quiet of the park... and notice how the two stories, art and coal, now share the same piece of land.