The usefulness of lighthouses on one of the busiest sea lanes in the world is fundamental, regardless of the performance of new navigational aids. Under Napoleon, signalling arrangements were put in place which included three lighthouses along the north coast: the ones in the Channel and the North Sea at Dunkirk, Calais, and the lighthouse "de la Canche" at Le Touquet-Paris-Plage. They are classified as historic monuments. As symbolic in our northerly regions as the fortresses, bell towers, and mills, they reflect an epic maritime history that is several centuries old. The architectural diversity of these sentinels of the sea must be explored, from lightships to lighthouses and lights whose bright glow guided so many mariners.