The broad interior lowland stretching from Poland through Belarus and Ukraine into western Russia. A continuous plain of chernozem soils, large river systems, and open steppe-edge transitions. Continental climate with hot summers and severe winters. Agrarian productivity is high, but the terrain offers minimal natural barriers. Structurally this is Europe’s dominant land-mass region—flat, exposed, and historically driven by cavalry, armies, and continental-scale states. You can treat it as the gravitational center of the Slavic and post-Kievan world.
