Penza, oblast (region), western Russia, occupying the western flank of the Volga Upland, which falls gently to the Oka–Don Plain in the extreme west. The oblast lies in the zone of forest-steppe. About one-fifth of its surface is in pine or oak forest, mostly in the Sura Basin, but natural vegetation has been widely plowed up, resulting in severe soil erosion. Agriculture, the major economic activity, is dominated by grain, especially winter rye and spring wheat. Hemp, sugar beets, and sunflowers are also grown. Engineering, the main industry, is concentrated in Penza city, the oblast headquarters, and Kuznetsk; the other cities are small and are mainly concerned with processing food and agricultural products. Timber working is important in the surviving forest areas, and paper is made. Area 16,680 square miles (43,200 square km). Pop. (2006 est.) 1,407,971.