The Volga is the longest river in Europe and the national river of Russia. It flows 3,530 kilometers through Central Russia and into the Caspian Sea. Historically, the Volga was a major meeting point for various Eurasian civilizations and served as an important trade route connecting Northern Europe with Central Asia and the Middle East. It drains a basin that covers nearly one-third of European Russia and contains many of the country's largest cities, including Moscow (via the Moscow Canal) and Volgograd. The river is heavily dammed for hydroelectric power and irrigation, and it is a major transport artery for moving goods across the Russian interior. The Volga is also famous for its sturgeon population, which produces the world's most prized caviar, though the construction of dams and pollution have significantly impacted sturgeon migration and spawning grounds over the last century.