Fortified Sector of Altkirch
Former French military organization / From Wikipedia, the free encyclopedia
The Fortified Sector of Altkirch (Secteur Fortifiée d'Altkirch) was the French military organization that in 1940 controlled the section of the French frontier with Germany and Switzerland in the vicinity of Basel. The sector's principal defense against an advance from Germany was the Rhine itself, which could be crossed only by boat or by seizing a bridge crossing. The frontier with Switzerland was not regarded as a high-risk location, save for a possible advance by German forces through Switzerland. Originally planned as a full extension of the Maginot Line with artillery ouvrages, the sector's fortifications were scaled back and chiefly took the form of casemates and blockhouses. The SF Altkirch adjoined the Fortified Sector of Mulhouse to the north and the Fortified Sector of Montbéliard to the west.