Caspian Sea

The Caspian Sea is the largest inland body of water and the third-deepest lake globally, dropping to 1,025 m in its South Caspian Basin. Bordered by Kazakhstan, Turkmenistan, Iran, Azerbaijan, and Russia, the Caspian Sea is the largest inland body of water on Earth and ranks as the third-deepest lake, reaching a maximum depth of 1,025 m in its southern basin. Limnologists and geologists classify the Caspian as an endorheic salt lake, representing an isolated remnant of the ancient Paratethys Sea that lost its connection to the world ocean approximately 5.5 million years ago. While the northern third of the Caspian is shallow with average depths of only 5 to 6 m, the South Caspian Basin features true oceanic crust covered by thick sedimentary layers, descending past 1,000 m. The lake covers a surface area of 371,000 km2 and holds 78,200 km3 of water, containing approximately 40% to 44% of the world's lacustrine waters.