Lake Urmia (a Syriac name meaning city of water), is the third largest salt lake on earth located in northwestern Iran.

The lake’s salts are considered to have medical effects, especially as a cure for rheumatism. The main cations in the lake water include Na+, K+, Ca2+, Li+ and Mg2+, while Clâ€", SO42â€", HCO3â€" are the main anions. The Na+ and Clâ€" concentration is roughly 4 times the concentration of natural seawater.

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. Although measures are now being taken to reverse the trend the lake has shrunken by 60 percent and could disappear entirely.

From March 2010, a series of serious protests and rallies demanding take action to save Lake Urmia was held in Iranian Azerbaijan.

Lake Urmia has 102 islands. The second largest island, Shahi Island, is the burial place of Hulagu Khan, the grandson of Genghis Khan and the sacker of Baghdad.