Saint Nicolas Tower along with the Lantern tower and the Chain tower, is one of the three medieval towers guarding the port in La Rochelle, France. In 1879 the French government classified it as a Monument historique.
Wikipedia https://en.wikipedia.org/wiki/Saint_Nicolas_Tower
Address 5 Rue de l'Armide, La Rochelle 17000, France
Coordinates 46°9'20.758" N -1°9'11.715" E