Lakes Far From the Sea: Salt, Drought and High Water

The largest inland body of water on Earth by surface area, at 371,000 square kilometers, and the right place to start. It is brackish rather than fresh, sits in a basin left by the ancient Paratethys Sea, and has no natural outlet to any ocean.

Once vast and now a small fraction of its former size, the Aral Sea shows what happens when the rivers feeding an inland salt lake are diverted. Soviet-era irrigation projects did this from the mid twentieth century, and its retreat is widely cited as one of the starkest human-caused environmental disasters.

Lake Balkhash in southeastern Kazakhstan is fresh in its western half and markedly saltier in the east, divided by a narrow strait. At about 16,400 square kilometers it is a neighbor of the Aral Sea in more than geography, since heavy diversion for irrigation raises concern that it could shrink the same way.

A change of setting: Issyk-Kul lies high in the Tian Shan of Kyrgyzstan and ranks among the largest alpine lakes in the world by volume. Its name means warm lake, because it rarely freezes despite the elevation and cold surroundings. Its area is about 6,236 square kilometers.

A salt lake in northwestern Iran of about 6,000 square kilometers that was once among the largest lakes in the Middle East. Decades of upstream damming and diversion sharply reduced it, and its high salinity historically supported little life beyond brine shrimp.

The largest lake in Turkey, about 3,755 square kilometers, set in the eastern highlands. It is an alkaline, closed-basin lake with no outlet to the sea, and its mineral-rich water supports one native fish species adapted to it.

The extreme case of a lake that comes and goes. This ephemeral salt lake in the arid interior of South Australia lies below sea level and fills only after exceptional inland flooding. When it does fill completely it covers up to 9,500 square kilometers, and when dry its cracked salt pan is one of the lowest points on the continent.

The largest permanent desert lake in the world, in northern Kenya and reaching into Ethiopia, covering about 6,405 square kilometers. Its alkaline, jade-green water contrasts with the arid land around it, and fossil discoveries here have shaped understanding of early human evolution.

The path ends high in the Andes, on the border of Peru and Bolivia, at generally the highest navigable lake in the world, above 3,800 meters. It covers about 8,372 square kilometers and was sacred to the Inca, who regarded it as the birthplace of their civilization.