Although it was built at the same time as most of the other forts in Belfort’s defensive belt, Fort Dorsner in Giromagny is unique in several respects. First and foremost, its architecture differs from the other Belfort fortifications. It is one of the few French forts to have an octagonal central courtyard and to be built of pink sandstone. 

Built between 1875 and 1879, it could house up to 650 men and around fifty artillery pieces. Its location close to the border ensured that it played a strategic role. It guarded the road leading down from the Ballon d’Alsace to Belfort. It also ensured that the Belfort stronghold could not be bypassed to the north. Its armament made it the most powerful fort in the area. In 1879, it was given an unusual defence with the installation of two Mougin turrets. They were the first ones to be installed in France. This armament was supplemented by six casemates and two artillery batteries. Fort Dorsner was occupied by the German army from 1940 to 1944, when it was used as an observation post. 

Abandoned until 1988, it was reacquired by the town of Giromagny. The Fort Dorsner Association works hard to give it a second life. Tours are available all year round for both younger and older visitors. Many events are also organised here, including concerts, exhibitions and themed evenings.