The Caspian Sea is the largest enclose body of water on Earth by area, variously classed as the world's largest lake or a full-fledged sea. It has a surface area of 371,000 square kilometers (143,244 sq mi) and a volume of 78,200 cubic kilometers (18,761 cu mi). It is an endorheic body of water (has no outflows), and lies between the southern areas of the Russian Federation and northern Iran. It has a maximum depth of about 1025 meters (3,363 ft). It was perceived as a sea by its ancient coastal inhabitants because it is salty and seemed boundless. It has a salinity of approximately 1.2%, about a third the salinity of most seawater.