Kyzylkak is an
endorheic lake located in the
Ishim Plain, south of the Russian border. It lies in the lowest part of a large depression and its shores are very steep. The bottom of the lake has a thick layer of black mud containing
magnesium salts and releasing
Hydrogen sulphide. Lake Kyzylkak is fed mainly by snow, but owing to its high
salinity it does not freeze in the winter. The Birsuat, Agynsay and Aksuat are the main rivers flowing into the lake. Depending on the rainfall the surface area of the lake varies between and on average. ==See also==