RUSSIAN PLAIN

also called East European Plain, Russian Russkaya Ravnina, or Vostochno-yevropeyskaya Ravnina, plain and series of broad river basins in eastern Europe (including western Russia). It extends over nearly 1,500,000 square miles (4,000,000 square km) and averages about 560 feet (170 m) in height. The plain is subdivided into a number of distinct regions, including the Valday Hills; the Central Russian Uplands; the Volga Uplands; and the Dnieper River, Black Sea, and Caspian Sea lowlands.