The Caspian Kara Kum ("Black Sand"), the larger desert at over 300,000 km², is east of the Caspian Sea, with the Aral Sea to the north and the Amu Darya river and Kyzyl-Kum desert to the northeast and covers 90 per cent of Turkmenistan. It is crossed by the Trans-Caspian railway and the largest irrigation canal in the world, the Kara-Kum Canal at 1375 km in length. The canal was started in 1954 and carries 13 km³ of water annually, unfortunately leakages from the canal has resulted in lakes and ponds along the canal and the rise in groundwater has caused widespread salinization. The area also has significant oil and natural gas deposits.
The Aral Kara Kum desert (40,000 km²) lies north of the Aral Sea in Kazakhstan.
