 Covering much of present-day Turkmenistan, the Karakum Desert lies east of the Caspian Sea, with the Aral Sea to the north and the Amu Darya river and the Kyzyl Kum desert to the northeast.In modern times, with the shrinking of the Aral Sea, the extended "Aral Karakum" has appeared on the former seabed, with an estimated area of 15,440 sq mi/40,000 km².Although the level of the Aral Sea has fluctuated over its existence, the most recent level drop was caused by the former Soviet Union building massive irrigation projects in the region.