On 20 January 1837, 16 harbour masters made the first official request for the establishment of "a harbour light that could be seen from two or three leagues out to sea and placed at the end of the Môle de Croix de Vie". The Vieux Môle tower was probably the port's first lighthouse.
Construction of the Josephine Tower, named after the empress, began in July 1851, and its light was commissioned in 1852. At 8 metres high and with a balustrade and light at the top, it marked the entrance to the port until 1875. The tower was then used as an explosives depot by the Ponts et Chaussées, hence the name "Dynamite Tower".
It was customary for newly-weds to go to the pier and make a round at the foot of the building. It was an omen of happiness! On 20 December 2000, after several months of restoration work, the Tour Joséphine, the city's oldest maritime structure, regained its crown and its 3.5 metre high lantern.