The Toktogul Zone includes the Ketmentebin intermountain basin in the lower reaches of the Naryn River, the Toktogul Reservoir, and the valley of the right tributary of the Naryn — Chychkan ("mouse"). The zone is located within the middle section of the famous Kyrgyz route Bishkek — Osh. Its center, the village of Toktogul, is located 190 km from the city of Talas. The city of Kara-Kul, located on the southern border of the zone, is 295 km away from Osh.
The Ketmentebin basin is smaller in area than the Talas basin. It is surrounded on all sides by high ridges: to the north — the Talas and Suusamyr ranges, to the east — the Kekirim-Tuu, and to the south and southwest — the Atoynok and Fergana ranges. The basin is dominated by semi-deserts and steppes. In the foothill zone surrounding the reservoir, there are steppes with chiy, prangos, cherries, and many other types of shrubs. From the reservoir and the water-rich Naryn River, the valley surface rises steeply to the slopes of the ridges. All flat areas remain at the bottom of the man-made sea. The names of the most significant areas of the valley bear the name of the great Kyrgyz akyn — Toktogul Satylganov, who celebrated the cherished places in his songs. Any Kyrgyz will point out Mount Shamsikal, the Toktobek-Say gorge, the Toktobek-Tuu mountains, and Ketmentebe. About Mount Shamsikal, located near the village of Torkent, T. Satylganov wrote:
“Shamsikal, oh, holy mountain!
Be kind to my household,
Share your salt with them,
White salt, whiter than silver.”
Even now, shepherds take salt for their sheep from this mountain.
From east to southwest, the valley is crossed by the water-rich Naryn River, which cuts through the mountain ranges with narrow and deep gorges. On the banks of the Naryn River, during the construction of the Toktogul Hydroelectric Power Station, the city of Kara-Kul was established. It is the youngest city (1977) in Kyrgyzstan. The city is built with modern, well-equipped houses with a high level of cultural and domestic services. Here live the builders of another major hydroelectric power station on the Naryn River — the Kurpsai.
10 km from Kara-Kul is the unique high-altitude dam of the Toktogul Hydroelectric Power Station. Its height is 227 m, the length along the crest is 350 m, and the base width is about 150 m. As a result of damming the Naryn River in the lowest part of the Ketmentebin basin at an altitude of about 800 m, the Toktogul Reservoir spread out as a wide man-made sea. It is the largest in Central Asia. The reservoir has a capacity of 20 billion cubic meters of water with a surface area of 284 square km. The dam is located in a narrow rocky canyon with almost vertical walls. Raising clouds of water dust, giant, twisted streams of foam burst from under the dam. In the canyon, the water color is dark green. As the depth decreases, its color becomes bluish, and in shallow waters — with a yellowish tint.
The Toktogul Sea supplies water to about 900 thousand hectares of arid lands in the Fergana Valley and the Hungry Steppe. The reservoir is home to marinka, zherekh, and Turkestan catfish. In the 1980s, carp, grass carp, white amur, Issyk-Kul trout, and Lena sturgeon were introduced here. The coastal areas provide ample opportunities for organizing summer recreation with swimming and water sports. On the southern shore of the reservoir is the "Uch-Terek" spring with salty water at a temperature of 22°. The local population uses this water for medicinal purposes.
To the northeast of the reservoir, in the basin of the Burlykiya and Tuzdusuu rivers, there are karst bowl-shaped depressions. In the picturesque area of Arym, there is a marble quarry, which has been used to clad many buildings in the capital of Kyrgyzstan.
