Urmia Lake is an endorheic salt lake in Iran.At its greatest extent, it was the largest saltwater lake on Earth, with a surface area of approximately 5,200 km2, a length of 140 km, a width of 55 km, and a maximum depth of 16 m. The lake has shrunk to 10% of its former size due to damming of the rivers that flow into it, and the pumping of groundwater from the surrounding area.