Lake Urmia is a salt lake in northwestern Iran, near Iran’s border with Turkey. The lake is between the provinces of East Azerbaijan and West Azerbaijan, west of the southern portion of the similarly shaped Caspian Sea. It is the largest lake in the Middle East, and the third largest salt water lake on earth, with a surface area of approximately 5,200 km² (2,000 mile²), 140 km (87 mi) length, 55 km (34 mi) width, and 16 m (52 ft) depth.
The lake Urmia is divided into north and south parts separated by a causeway in which a 1500m gap provides little exchange of water between the two parts. Due to drought and increased demands for agricultural water in the lake’s basin, the salinity of the lake has risen to more than 300 g/L during recent years, and large areas of the lake bed have been desiccated. Here, salt flats ring the lake’s shores, particularly on the southern end.