Lake Urmia was once the planet’s sixth largest salt lake. But after gradually receding for years, the water body shriveled last year to a mere 10% of its maximum. Iran plans to spend about $6 billion over the next decade on Urmia’s revival–the largest environmental project in the country. To get a sense of the scale of the problem Iran faces, I spent 2 days at the end of July at the lake with Hossein Akhani, a botanist at University of Tehran who studies salt-loving plants. I found an ecosystem under siege. View the full feature story on saving Iran's great salt lake.