A salt lake or saline lake is a landlocked body of water which has a concentration of salts (mostly sodium chloride) and other minerals significantly higher than most lakes (often defined as at least 3,000 milligrams of salt per liter). In many cases, salt lakes have a higher concentration of salt than sea water.
Formation
Salt lakes form when the water flowing into the lake, containing salt or minerals, cannot leave because the lake is endorheic or terminal. The water then evaporates, leaving behind any dissolved salts and thus increasing its salinity, making a salt lake an excellent place for salt production.
High salinity will also lead to a unique flora and fauna in the lake in question.
Salt lakes artificially built for this purpose are called salt pans.
When the water is gone
If the amount of water flowing into a lake is less than the amount evaporated, the lake will eventually disappear and leave a salt flat or playa (sometimes also referred to as salt pan).
Records
In order, the four largest salt lakes in the world are the Caspian Sea, the Aral Sea, Lake Balkhash and Great Salt Lake, which is also the largest in the Western Hemisphere. The salt lake with the highest elevation is Namtso, and the one with the lowest elevation is the Dead Sea, which is also the lowest exposed point on the Earth's surface.