The Caspian Sea is connected to the Black Sea via the Volga River system. These waterways facilitate transportation and commerce, impacting the economies of the surrounding regions. The Caspian Sea, the world's largest enclosed inland body of water, is bordered by several countries, including Russia, Kazakhstan, Azerbaijan, Iran, and Turkmenistan. It plays a crucial role in regional ecology, fishing, and oil extraction, significantly influencing the geopolitical landscape.