Casemate d ' Oberroedern Sud The Casemate d ' Oberroedern Sud , also known as Casemate Reiffel and Oberroedern Est , is a pre - World War II fortified position near the Rhine river in eastern France . The casemate was part of an extension of the Maginot Line fortifications along France ' s border with Germany . As a unit of the Fortified Sector of Haguenau , the casemate was part of French defenses in June 1940 . It has been preserved and is a component of a museum focusing on the Rhine section of the Maginot Line . The museum is located at the eastern edge of the town of Oberrœdern . Concept and design . Unlike other portions of the Maginot Line , the Rhine defenses were not interconnected , consisting of individual casemates or blockhouses a few hundred meters apart , arranged to fire along the length of the defended frontier . In initial planning , a Maginot " ouvrage " with several combat blocks , interconnected and served by underground galleries , barracks and magazines , was planned for Oberroedern . The plan was reduced to two separate casemates , Oberroedern Nord and Sud . The casemate is arranged on two levels , with living facilities and utilities on the lower level and combat stations on the upper level . The casemate fired to the north and south along the casemate line , and an 37mm anti - tank gun / JM machine gun combination firing to the south and an AC37 / JM firing to the north , with a JM machine gun firing to the west . . A GFM cloche on the top of the casemate allowed for protected observation . Firing ports for light automatic rifles covered the entrance and the area around the casemate . Manning . The casemate was commanded after September 1939 by Lieutenant Rieffel , with twenty troops from the 79th Fortress Infantry Regiment . 1940 . The area around Hoffen and Oberroedern saw the heaviest fighting along the Rhine defenses during the Battle of France in June 1940 . On 12 June the casemate was attacked by German Stuka dive bombers , while German patrols infiltrated the country nearby . On June 20 the German 246th Infantry Division attacked several casemates centering on Oberroeden Nord and Aschbach - Ouest and Est . Aerial bombing hit Oberroeden Nord and the Abri de Hoffen , disrupting communications but not seriously harming the French defenses . German artillery hit an embrasure at Oberroeden Sud , killing Sergeant Delsart , who was buried that night just outside . Despite the intensity of the attack , the casemate line , aided by the Maginot " ouvrages " Hochwald and Schoenenbourg , held . On 24 June the casemate was abandoned on orders from the French command and its garrison was taken into captivity . The nearby Oberroedern Nord casemate came under heavy aerial attack at the same time as Onberroedern Sud . A bomb that fell into the ' fosse ' ( ditch ) outside the casemate ' s entrance exploded with sufficient force to lift the casemate , briefly panicking the garrison . Preservation . The Casemate d ' Oberroedern Sud is maintained as " Casemate Rieiffel " by the " Association des Amis de la Ligne Maginot d ' Oberroeden " , which has maintained the casemate since 2001 . The organization also overseess the casemates at Aschbach Est ( " Casemate Beck " ) , Aschbach Ouest ( " Casemate Linger " ) and Bois d ' Hoffen , however these are not presently open to the public .