To house the new prisoners, three new camps were established: Flossenbürg (May 1938) near the Czechoslovak border, Mauthausen (August 1938) in territory annexed from Austria, and Ravensbrück (May 1939) the first purpose-built camp for female prisoners. The mass arrests were partly motivated by economic factors. Recovery from the Great Depression lowered the unemployment rate, so "work-shy" elements would be arrested to keep others working harder. At the same time, Himmler was also focusing on exploiting prisoners' labor within the camp system. Hitler's architect, Albert Speer, had grand plans for creating monumental Nazi architecture. The SS company German Earth and Stone Works (DEST) was set up with funds from Speer's agency for exploiting prisoner labour to extract building materials. Flossenbürg and Mauthausen had been built adjacent to quarries, and DEST also set up brickworks at Buchenwald and Sachsenhausen.