The Caspian Sea is the largest enclosed inland body of water on Earth, bordered by five countries: Russia, Kazakhstan, Turkmenistan, Iran, and Azerbaijan. It is classified as a lake, despite its name, and has a surface area of about 371,000 square kilometers. The sea is known for its unique biodiversity, including the famous Caspian seal and various fish species, such as sturgeon, which are prized for their roe. The Caspian Sea is also significant for its natural resources, particularly oil and natural gas reserves. Its surrounding regions have been the focus of economic development and geopolitical interests, leading to various environmental and territorial disputes. The sea plays a crucial role in the local economies and cultures of the bordering nations.