The body of water that is the second-largest inland body of water in the world is the Caspian Sea. Despite its name, it is classified as a lake due to its closed basin and lack of connection to the world ocean. The Caspian Sea is bordered by five countries: Russia, Kazakhstan, Turkmenistan, Iran, and Azerbaijan. It is significant for its diverse ecosystems and rich natural resources, including oil and gas reserves. The unique characteristics of the Caspian Sea offer opportunities for various activities, such as fishing and tourism, contributing to the economies of surrounding nations.