For most of its history, Calais was really two places: the medieval port clustered around Notre-Dame on the north side of the Canal de Calais, and Saint-Pierre, an inland working town gathered around its own church on the south bank. In 1885 the two municipalities formally merged, and a quiet argument began over where the new joint government should sit. Putting it in either old centre would feel like surrender. So in 1911 the council chose the no-man's-land between them, the windblown sand belt that had separated the towns for centuries. The new Hôtel de Ville would be a building literally and symbolically built on the seam, holding two communities together. The First World War interrupted everything; a German bomb struck the half-finished walls on the night of 3 September 1917. The project simply waited out the war and resumed.

Louis Debrouwer, an architect from Dunkirk, drew the building in a Flemish Renaissance Revival idiom that nods hard at Belgium, Calais's neighbour just up the coast. He used red brick from Kortrijk and white limestone in alternating bands, an unmistakable northern-European combination that signals Bruges and Antwerp more than Paris. The asymmetrical west front faces the Place du Soldat Inconnu. The belfry rises 72 metres on the north end of the site, deliberately designed in the silhouette of a flame, narrowing and curling toward the sky. The building was officially opened on 12 April 1925, fourteen years after construction began. In 2005 the belfry joined the UNESCO World Heritage Site list of Belfries of Belgium and France, the cross-border ensemble of medieval and revival towers that mark this old textile-and-trade landscape. The tower is the easiest navigation point in Calais; you find it before you find anything else.

Stand in front of the Hôtel de Ville and you will see Auguste Rodin's six bronze figures, The Burghers of Calais, walking out toward you with ropes around their necks. Eustache de Saint Pierre and five other leading citizens are remembered for surrendering themselves in 1347 to Edward III of England to save their starving city from massacre at the end of an eleven-month siege. Rodin refused to put them on a pedestal. He wanted them at ground level, eye-to-eye with the people they died for, dragging their feet toward an English king. Inside the town hall, a tapestry by Jeanne Thil depicts the same scene, and stained-glass windows tell a related story: the 1558 liberation of Calais by François, Duke of Guise, who finally pried the port back into French hands after 211 years of English rule.

Inside, a grand wedding hall has hosted thousands of civil marriages. The hall is best known to outsiders as the room where, in modern times, Calais residents gather around the mayor on Bastille Day. In the autumn of 1944 the building took fire again. Many parts of Calais were heavily damaged in the fighting, including the Grand Theatre, before the First Canadian Army liberated the town on 30 September. The Hôtel de Ville was patched, rebuilt where it had to be, and continued to do what it had been built to do: hold together a place that had spent a millennium being argued over by France, England, Burgundy, Spain, and Flanders. The flame-shaped tower stayed lit.

Belfries are unusual buildings. In the Low Countries and northern France, they grew in the Middle Ages not as church towers but as civic ones, paid for by merchants and weavers and trade guilds rather than bishops. To build a belfry was a town's way of saying we govern ourselves. The clock in the tower belonged to the citizens. The bells rang for fairs, fires, and the calling of councils, not for Mass. Calais's belfry is one of the youngest in the UNESCO group, finished in 1925 rather than 1325, but it speaks exactly the same language as the medieval ones in Bruges and Tournai. Two centuries from now it will still be the first thing you see crossing the Channel.