The sky-blue lake of Kel-Suu is located in the valley of Kok-Kiya at the altitude of 3514 m, between high rocky mountains. It was formed thousands of years ago, because of the destruction of the mountain massif. Therefore, it has an elongate shape: the length of it is 9 km and its width is 0.5-2 km.
From all sides Kel-Suu is surrounded by steep cliffs with numerous caves and pits. In the middle of the lake there is a small stone island. To enjoy the spectacular views of the lake it is recommended to have a small voyage in a boat across it.