The Caspian Sea (Russian: Каспи́йское мо́ре, Azerbaijani: Xəzər dənizi, Kazakh: Каспий теңізі, Persian: دریای خزر, Turkmen: Hazar deňizi, Rutul: Kaspy der'ya) is the largest enclosed inland body of water on Earth by area, variously classed as the world's largest lake or a full-fledged sea. The sea has a surface area of 371,000 km2 (143,200 sq mi) (not including Garabogazköl Aylagy) and a volume of 78,200 km3 (18,800 cu mi). It is in an endorheic basin (it has no outflows) and located between Europe and Asia. It is bounded to the northeast by Kazakhstan, to the northwest by Russia, to the west by Azerbaijan, to the south by Iran, and to the southeast by Turkmenistan. The Caspian Sea lies to the east of the Caucasus Mountains and to the west of the vast steppe of Central Asia. Its northern part, the Caspian Depression, is one of the lowest points on Earth.
The ancient inhabitants of its coast perceived the Caspian Sea as an ocean, probably because of its saltiness and large size. It has a salinity of approximately 1.2% (12 g/l), about a third of the salinity of most seawater.