Gravelines sits right where the river Aa meets the Channel, between Calais and Dunkirk, and it still wears its walls. The town is wrapped in Vauban-era fortifications, a star of brick ramparts, bastions and water-filled moats that you can walk or ride around, and in the middle of it rises the belfry, one of the towers listed by UNESCO among the belfries of northern France and Belgium. It is a solid, sober tower rather than a showpiece, built to watch, warn and ring the hours for a frontier town that changed hands more than once.
The history here is seaborne. In 1588, off this stretch of coast, the English fleet sent fireships into the anchored Spanish Armada and the running fight that followed, usually called the Battle of Gravelines, broke the Armada's formation for good. Thirty years earlier a land battle near the town had gone the other way for the French. Walk out to the mouth of the Aa at Grand-Fort-Philippe and you look over the same grey water, now busy with fishing boats and the occasional sailing club dinghy.
Modern Gravelines has another landmark you cannot miss: the nuclear power station on the coast just east of town, one of the largest in Europe. It makes for a strange backdrop to a seventeenth-century fortress, and the warm water it releases is said to be good for the local fish farming.
The riding is coastal and flat, so honesty is in order: you come here for atmosphere, not for corners. The D940 heads west along the Côte d'Opale towards Calais and the white cliffs of Cap Blanc-Nez, and that stretch is a lovely ride with big skies, dunes and sea light that changes by the minute. Wind is the defining feature and gusts off the Channel can be fierce, especially in autumn. Watch for cobbles inside the ramparts and the tight gates through the walls.
With thirteen thousand people, Gravelines has fuel, supermarkets and a good choice of brasseries; fish and seafood are the obvious order, and moules-frites never feels wrong this close to the water. The ramparts make a fine place to walk off lunch and look out across the moats while the bike cools down.