The Rheinwiesenlager were a group of 19 concentration camps built in the Allied-occupied part of Germany by the U.S. Army to hold captured German soldiers at the close of the Second World War. Officially named Prisoner of War Temporary Enclosures, they held between one and almost two million surrendered Wehrmacht personnel from April until September 1945.
Prisoners held in the camps were designated disarmed enemy forces, not prisoners of war. This decision was made in March 1945 by SHAEF commander in chief Dwight D. Eisenhower: by not classifying the hundreds of thousands of captured troops as POWs, the logistical problems associated with accommodating so many prisoners of war mandated by the Geneva Convention governing their treatment were negated.
Wikipedia https://en.wikipedia.org/wiki/Rheinwiesenlager
Address 53 Rheinallee, Sinzig 53489, Germany
Coordinates 50°32'53.831" N 7°16'9.699" E