Aigues-Mortes is one of the most complete medieval walled towns in France — a perfect rectangle of golden ramparts standing alone in the flat marshes of the Camargue, in Occitanie in the far south. It was founded in 1240 by King Louis IX, later canonised as Saint Louis, who needed a Mediterranean port that answered to the French crown alone rather than to the Italian maritime republics or a foreign lord. On this reclaimed salt-marsh — the name means 'dead waters' — he laid out a new town on a grid and began the great cylindrical keep now called the Tour de Constance. From here, in 1248 and again in 1270, Saint Louis set sail with his fleets for the Seventh and Eighth Crusades.
The ramparts that ring the town were built through the thirteenth and fourteenth centuries, the walls begun in earnest under his son Philip III the Bold from 1272 and completed over the following decades. Because Aigues-Mortes was never remodelled or heavily restored in the nineteenth century, its 1,650-metre circuit of walls, gates and towers survives almost exactly as it was raised — an unbroken medieval enceinte you can walk the whole way round, looking out over the town's chequerboard of streets on one side and the shimmering salt lakes of the Salins du Midi on the other.
At the northwest corner stands the Tour de Constance, the mightiest of the towers, built by Louis IX between 1242 and 1254 with walls six metres thick at the base. In later centuries it became a prison, and after the Revocation of the Edict of Nantes in 1685 it held Huguenot women who refused to renounce their Protestant faith. The most famous of them, Marie Durand, was imprisoned here for thirty-eight years; on the stone kerb of the tower's well she is said to have carved the single Occitan word 'RÉSISTER' — resist — which visitors can still read today. Managed by the Centre des monuments nationaux, the monument is a self-guided visit: climb the tower, walk the walls, and let 750 years of history unfold around you.