It lies between Kazakhstan in the north and Karakalpakstan, an autonomous region of Uzbekistan, in the south. The name roughly translates as "Sea of Islands", referring to more than 1,500 islands of one hectare or more that dotted its waters.
In Old Turkic 'aral' means an "island" and also a "thicket".
The Aral Sea, like the Caspian Sea and Black Sea, is a remnant of the ancient Paratethys Sea. It became landlocked about 5.5 million years ago due to a fall in sea level and the uplift of the Elburz and Caucasus Mountains. It is generally believed that the Amu Darya did not flow into the shallow depression that now forms the Aral Sea until the beginning of the Holocene, and it is known that the Amu Darya flowed into the Caspian via the Uzboy channel until the Holocene. The Syr Darya formed a large lake in the Kyzyl Kum duirng the Pliocene known as the Mynbulak depression.