The establishment of the town of Saint-Malo – “whose extent is not equal to that of the Tuileries”, according to the writer François-René de Chateaubriand – was a real challenge to nature. Another disadvantage was that the city’s rugged perimeter was cut off from the rest of the world at high tide, with only the Sillon connecting it to the mainland. And unlike other large port cities, it has no real waterways to transport goods into the hinterland. Nevertheless, the rocky mound surrounded by islets, reefs and dangerous currents became the leading port of France in the time of Louis XIV, ahead of Le Havre and all the ports of the Atlantic facade.