Kura (Caspian Sea) emptying into the Caspian Sea at Neftçala. Most of the Kura River runs in the broad and deep valley between the Greater Caucasus and Lesser Caucasus mountains, and the major tributary, the Aras, drains most of the southern Caucasus and the mountain ranges of the extreme northern Middle East. The entirety of Armenia and most of Azerbaijan are drained by the Kura River, but the Kura does not pass through Armenia at all. Also in the Kura watershed are Turkey, Georgia, and a bit of northern Iran. Most of the elevation change in the river occurs within the first .
Caspian Sea human settlements. The Caspian has characteristics common to both seas and lakes. It is often listed as the world's largest lake, although it is not a freshwater lake. It contains about 3.5 times more water, by volume, than all five of North America's Great Lakes combined. The Caspian was once part of the Tethys Ocean, but became landlocked about 5.5 million years ago due to plate tectonics. The Volga River (about 80% of the inflow) and the Ural River discharge into the Caspian Sea, but it has no natural outflow other than by evaporation. Thus the Caspian ecosystem is a