Twenty-eight sketches of the Auschwitz concentration camp that Germany’s chief archivist called the plans “of extraordinary importance” have been found in a Berlin apartment following the inhabitant’s death, the Guardian reports. The plans show barracks, gas chambers, and “L. Keller,” an abbreviation for leichenkeller or corpse cellar, providing evidence that Auschwitz was built for killing from the very start. Historians believe that on January 20, 1942, top Nazi officials met and created the “final solution,” but one of the blueprints dates from eight months earlier and would represent a major find. The plans were found on the 70th anniversary of Kristallnacht, the pogrom that preceded the Holocaust.