Fort Jeanne d'Arc, also called Fortified Group Jeanne d'Arc, is a fortification located to the west of Metz in the Moselle department of France. It was built by Germany to the west of the town of Rozérieulles in the early 20th century as part of the third and final group of Metz fortifications. The fortification program was started after the German victory of the Franco-Prussian War, which resulted in the annexation of the provinces of Alsace and Lorraine from Germany to France. The Fort Jeanne d'Arc was part of the Moselstellung, a group of eleven fortresses surrounding Thionville and Metz to guard against the possibility of a French attack aimed at regaining Alsace and Lorraine, with construction taking place between 1899 and 1908. The fortification system incorporated new principles of