Porte Saint-Martin

Stand still for a moment and listen. Buses sigh past on the boulevard. Scooters weave through the traffic. Then raise your eyes to the stone above them. The surface is not smooth. It is carved into deep, wandering grooves, as if worms had tunnelled across every block. This is Porte Saint-Martin, a triumphal arch from the reign of Louis XIV. It still stands in the middle of a working Paris street, and the city flows around it every day.

The arch was built in 1674, during the reign of Louis XIV, the king the French remember as the Sun King. He ruled France for more than seventy years. He loved images of his own glory. In Paris he chose to show that glory with gates of stone, built in the style of ancient Rome. This arch is one of two such monuments that still survive on this stretch of the boulevards. Its larger sister, Porte Saint-Denis, stands just a short walk to the west.

Here is the first surprise. This was once a real gateway in a real wall. For centuries, Paris was enclosed by fortifications, and the road below you passed through them. Rue Saint-Martin runs south toward the river, and its route is very old. As the king's armies grew stronger, Louis decided that Paris no longer needed walls. The old ramparts came down. In their place, the city laid out wide, tree-lined promenades. Parisians called them the boulevards, and that is the street you are standing on now.

So the gate lost its defensive purpose... and gained a new one. It became a monument. The architect was Pierre Bullet, a pupil of François Blondel, the man who designed Porte Saint-Denis. Bullet gave his arch three openings. There is a tall central passage and two smaller side passages. That arrangement echoes the triumphal arches of the Roman emperors. A Parisian in the seventeenth century would have understood the message at once. The king was a new Caesar.

Look closely at that grooved stone again. This technique is called vermiculated rustication. The word comes from the Latin for worm. Masons cut the surface into irregular, twisting channels. Up close, the effect is rough and almost organic. From a distance, it gives the arch weight and shadow, even on a grey afternoon. It took enormous patience to carve. Every winding line on these blocks was shaped by hand, with chisels and mallets.

Now find the attic, the band of stone across the very top. There you will see a Latin inscription. It praises the king as Louis the Great, Ludovico Magno. The inscriptions also explain why the arch exists. It celebrates military victories of the 1670s. These include the capture of Besançon and the conquest of the Franche-Comté, a region in eastern France that had belonged to the Spanish crown. It also honours the defeat of the armies of the German states, the Dutch and the Spanish.

Between the arches you will find large carved panels, called bas-reliefs. Several sculptors worked on them, among them Martin Desjardins and Étienne Le Hongre. Each panel tells part of the story of the war in the language of myth. There are captured cities, defeated enemies and the figure of Fame. The carving is deep enough to catch strong shadows when the sun moves across the stone. The panels differ on each side, so it is worth walking around the arch.

And here is the second surprise — one that most passers-by never notice. In one of the panels, Louis XIV appears as Hercules, the hero of Greek myth. He is almost naked, with a club in his hand. Yet he still wears his enormous curled wig. To modern eyes, the combination looks a little comic. To the court of the time, it made perfect sense. The wig marked the king. The muscular body marked the hero. Together they told the viewer that the king was strong, victorious and almost divine.

The arch is roughly eighteen metres tall, about the height of a six-storey building. Today, apartment blocks crowd close to it, and the arch can feel almost modest. Picture it instead in the late seventeenth century. The buildings around it were lower. The boulevard was new and open. Carriages rolled under the central passage, and the stone was pale and fresh. Then it would have dominated the skyline of this edge of Paris.

Now look along Boulevard Saint-Martin, to the east of the arch. In some stretches, the pavements sit higher than the road, with railings and steps. This is a trace of nineteenth-century engineering. The city lowered the roadway to make the slope gentler for traffic. The old ground level survived on the sidewalks. It is a small detail, but it shows how much Paris has been reshaped beneath the feet of the people who live here.

The neighbourhood around the arch has always been a place of entertainment. Just beside it stands the Théâtre de la Porte Saint-Martin, one of the city's historic playhouses. In the nineteenth century, these boulevards were famous for popular theatre, melodrama and crowds out for an evening. Today you will find cafés, kebab shops, hair salons and small bars. People wait here for buses, meet friends and argue on their phones. The royal monument has become part of an ordinary, very lived-in corner of Paris.

As you walk around the arch, notice how the stone has aged. Some surfaces are pale and clean after restoration. Others carry the darker stains of traffic and weather. You can see small repairs where blocks were patched or replaced. The arch is not a frozen relic behind glass. It stands in the open air, in the dust and noise of a modern city. That exposure is part of its character. It has watched centuries of Parisian life go by.

Before you move on, take one last look up at the central passage. Let your eye travel from the grooved blocks to the carved panels, and then to the Latin words at the top. A king built this to tell the world that he had won. Today, the traffic simply passes beneath it. Listen for the buses again, the voices, the clink of glasses from a nearby café... and notice how calmly the old stone holds its place above them all.