The Aydar Lake (Uzbek: Aydar Ko‘li, Айдар кўли; Haydar ko‘li, Ҳайдар кўли; alternate spellings: Lake Aydarkul, Lake Aidarkul) is part of the man-made Aydar-Arnasay system of lakes, which covers an area of 4,000 square kilometres (1,500 mi²). This system includes 3 brackish water lakes (Aydar Kul, Arnasay and Tuzkan) located in the saline depressions of the south-eastern Kyzyl Kum (now in Uzbekistan and Kazakhstan).