What makes the Caspian Sea unique?

The Caspian Sea is unique because it is the world's largest enclosed inland body of water, classified as both a lake and a sea. It is bordered by five countries: Russia, Kazakhstan, Turkmenistan, Iran, and Azerbaijan. Additionally, the Caspian Sea has a distinct ecosystem, with a mix of freshwater and saltwater species, and it is home to the famous Caspian seal and sturgeon, the latter being a source of prized caviar. Its geopolitical significance and rich Natural Resources, including oil and gas reserves, further enhance its uniqueness.