Not only on the Eastern Front, the treatment of Russian military and civillian prisoners used to build the Atlantic Wall happned on UK soil. The Island Alderney also had four concentration camps. Nordeney, Borkum, Sylt and Helgoland.
The mother of friend of mine used to hate the sound of wood being chopped. When she was a child her bedroom was adjacent to a hill called La Route De Fancfief. The prisoners were marched up the hill to work at about 5 am every morning. Those that had anything on thier feet, had wooden flip flops or sandals that echoed off the road. There are also authenticated stories of those who died during construction of the fortifications being cemented into them. The Orginsation Todt, were known locally as Greenfly, due to the colour of the uniform and they were a pest.