Lake Urmia is an endorheic salt lake in Iran. The lake is located between the provinces of East Azerbaijan and West Azerbaijan in Iran, and west of the southern portion of the Caspian Sea. At its greatest extent, it was the largest lake in the Middle East and the sixth-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. Lake Urmia, along with its approximately 102 islands, is protected as a national park by the Iranian Department of Environment.