Lake Urmia is an endorheic salt lake in northwestern Iran. It was once the sixth-largest saltwater lake on Earth with a surface area of 2,000 square miles (5,200 square km), but by 2017 had shrunk to 10% of its original size due to drought and damming of inflow rivers. The lake’s red-orange color comes from a high concentration of halophiles, or “salt-loving” bacteria and algae, which have pigments ranging from pink to deep red.