All the rivers of this region that carry their waters from high mountains flow into lake Balkhash, however, none of them flows out. The major ones are : Ili, Aksu and Karatal. The lake is divided into two parts by the Saryesik peninsula (which means Yellow Door in the Kazakh language). These two parts are connected by the Uzynaral strait. In ancient times Balkhash was much larger and was many lakes in the area were part of it (including lakes Zhalanashkol, Alakol and Sasykkol). Once it was even a sea, stretching all the way to the Dzungarian Alatau.