Saint-Omer is one of those quietly rewarding French towns that rewards you for stopping rather than driving through. It was a major trading city in the Middle Ages — positioned on the border between Flanders and Artois — and its old market square and the atmospheric ruins of Saint-Bertin Abbey still hint at that former importance. The abbey is where the last Merovingian king died in the late seventh century, which is the kind of historical footnote that makes wandering these streets feel surprisingly weighty.
What makes Saint-Omer truly distinctive, though, is the marais audomarois — a living wetland of canals and market gardens on the edge of town where farmers have grown vegetables for centuries, selling their produce from flat-bottomed boats. It's an unexpected slice of working rural life just minutes from the town centre.
The locals are genuinely among the friendliest you'll meet in northern France. That alone is worth a detour.
Note: Saint-Omer has no train station. The nearest rail connection is Hazebrouck, about 20 km away.