Black Sea–Caspian Steppe Terek River. Between these the rivers are caught by the Malka River which is an east-flowing tributary of the Terek. In the west, since the Caucasus Mountains run parallel and close to the Black Sea coast, no significant rivers from this area reach the Black Sea. The western point is the Taman Peninsula. North of the Taman Peninsula the Kuban River, the Beysug River and the Yeya Rivers reach the Sea of Azov, and the long Manych River and the shorter Sal River reach the lower Don. In the north much of the lower Don is under the Tsimlyansk Reservoir
Caspian Sea closed basin, with its own sea level history that is independent of the eustatic level of the world's oceans. The level of the Caspian has fallen and risen, often rapidly, many times over the centuries. Some Russian historians claim that a medieval rising of the Caspian, perhaps caused by the Amu Darya changing its inflow to the Caspian from the 13th century to the 16th century, caused the coastal towns of Khazaria, such as Atil, to flood. In 2004, the water level was below sea level. Over the centuries, Caspian Sea levels have changed in synchrony with the estimated discharge