Between them, Russia and the Caucasus extend from Eastern Europe across the whole of the North of Asia to the North Pacific. The Caucasus (Caucasia) itself is a region in Eurasia bordered on the north by Russia, on the east by the Caspian Sea, on the south by Turkey and Iran in Asia and on the west by the Black Sea. The Caucasus Mountains are commonly considered to be the natural boundary between Asia and Europe, and territories in Caucasia are variably considered to be in one or both continents.
