The body of water known as the world’s largest inland body of water is the Caspian Sea. Despite its name, it is classified as a lake due to being landlocked. Covering over 371,000 square kilometers, it is bordered by five countries: Russia, Kazakhstan, Azerbaijan, Iran, and Turkmenistan. The Caspian Sea is an essential ecological zone, rich in biodiversity, particularly known for its unique species, including the famous sturgeon fish.