Of the five prewar concentration camps where economic industries were prominent, Flossenbürg was the one that was most significant and consistent in producing income for DEST. For example, it produced of stone in 1939, almost three-quarters of the total production that year. The largest buyer of Flossenbürg granite was Albert Speer's office for the reconstruction of Berlin. Within this project the largest and most significant orders were for Wilhelm Kreis' Soldiers' Hall ("Soldatenhalle") project, beginning in 1940. Increasing amounts of stone were used for road building; 15% in 1939 but 60% the next year.