The Caspian Sea is located in a basin that may be as old as 250 million years and was connected to the Mediterranean until about 12 million years ago. Between four and five million years ago, the Caspian Sea was about a third of its present size. Around three million years the Black Sea, Aral Sea and Caspian Sea were a true sea connected to the Mediterranean Sea and the world oceans by the Sea of Azov. During the ice age between 10,000 and 8,000 years ago the Caspian Sea was about two thirds the size it is now.
