Which sea is often described as the world's largest lake?

The Caspian Sea is often described as the world’s largest lake.

This enormous inland water body has no natural outlet to the ocean, making it an endorheic basin. Its surface lies below global sea level, and evaporation balances inflows from rivers, especially the Volga, which supplies roughly 80% of its water.

Although called a sea, the Caspian is not ocean-connected and is slightly saline, with salinity around 1.2%. Its classification reflects a mixture of geography, history, and convention: it has lake-like hydrology but sea-like size, waves, and salinity.

The Caspian borders Azerbaijan, Iran, Kazakhstan, Russia, and Turkmenistan. It is also famous for sturgeon fisheries and caviar, while pollution, river dams, and falling water levels threaten its ecosystem.