Caspian Sea the east often changed course to empty into the Caspian through a now-desiccated riverbed called the Uzboy River, as did the Syr Darya farther north. The Caspian also has several small islands; they are primarily located in the north and have a collective land area of roughly . Adjacent to the North Caspian is the Caspian Depression, a low-lying region below sea level. The Central Asian steppes stretch across the northeast coast, while the Caucasus mountains hug the western shore. The biomes to both the north and east are characterized by cold, continental deserts. Conversely, the climate to the southwest
Black Sea–Caspian Steppe Azov broke off and formed the Lesser Nogai Horde, a name that gradually went out of use. Around 1630 the Kalmyks migrated west from Dzungaria and occupied the land around the north end of the Caspian Sea, driving the Nogais south and west. In 1771 a significant part of them returned to Dzungaria and the Nogais returned east and north. A few Russians were on the lower Terek by about 1520 and Cossacks were somewhere on the Don by 1550. In 1556 Russia took Astrakhan and interacted with Kabardia for a few years before losing interest in the area south