Frankfurt-Heddernheim concentration camp, Labor education camp in Heddernheim, Frankfurt, Germany.

The Arbeitserziehungslager Heddernheim was the only labor education camp in Frankfurt am Main, set in the excavated clay pit of a former brickworks at Oberschelder Weg, corner of Zeilweg, on the northern edge of Heddernheim. The grounds covered about 1,250 m² and, according to eyewitnesses, held three long prisoner barracks, several sheds, a small guard hut at the entrance, a guard room, a watchtower, a "bunker" used as a prison, a delousing bath, a dog kennel and an roll-call square between the barracks.

The Arbeitserziehungslager Heddernheim operated from 1 April 1942 to 18 March 1945, the only labor education camp in Frankfurt am Main. It stood in the excavated clay pit of a former brickworks at Oberschelder Weg, corner Zeilweg, on the northern edge of Heddernheim. About 10,000 Germans and foreigners were held there. The Frankfurt Gestapo's camp records burned before the war's end, and a small memorial has commemorated the site since 1986.

Residents called the site Kull, a local dialect word for clay pit, and later Kajenn, after the French penal colony on Devil's Island. Prisoners, dressed in blue, were nicknamed the Blaue Division. Since 1986 a small memorial has marked the former clay pit at Oberschelder Weg, corner Zeilweg.

The site is accessible to visitors today and offers educational materials about the camp's history. A visit can be combined with other memorial sites in Frankfurt for a more complete understanding.

The camp was nicknamed Kajenn after the French penal colony on Devil's Island, and prisoners were called the Blaue Division because of their blue clothing. The site, about 1,250 m² in a former clay pit, was traditionally known by residents as Kull, a dialect word for clay pit.