Located in the south of the Naryn region, it is bordered to the north by the At-Bashinsky and Jangi-Jer ridges, and to the south by the so-called Kak-Shaal-To ridge, specifically its western part. The state border with the People's Republic of China runs along the Kak-Shaal-To ridge. The Ak-Sai Valley itself is a wide high-altitude valley stretching from the southwest to the northeast. The valley floor rarely drops below 3000 meters above sea level, sometimes reaching nearly 4 kilometers in height in its upper reaches. The highest point of the Kak-Shaal-To ridge within the Ak-Sai Valley is the inaccessible peak at 4960 meters, located on the border with China.
The climate of the valley is sharply continental. Frequent night frosts in summer are followed by a significant rise in temperature during the day. The valley is a kind of Kyrgyz pole of cold. The minimum temperature recorded here during observations has dropped to -56 degrees Celsius. At the same time, the maximum summer temperature reaches +33.
The valley is covered with short but very dense grass, abounding in small marshes and lakes, with huge boulders scattered throughout the valley. It is constantly windy and sunny here. The main rivers of the valley are Ak-Sai, Mydyryum, and Kyok-Kiya, which merge to form the river Kakshaal, cutting through the Western Kak-Shaal-To ridge and, after merging in China with two other rivers, Uzyongyu-Kuush and Sary-Jaz, which have also carved their way through this ridge in its central and eastern parts respectively, carry their muddy waters into the Tarim River. The Ak-Sai River is abundant in water, flows in a wide channel, often branching off, and has many tributaries. It does not belong to the Naryn basin.
The valley is home to many birds: snow sparrows, red-breasted flycatchers, masked wagtails, saker falcons, ruddy shelducks, common kestrels, mountain larks, sandpipers, bearded vultures, black vultures, bearded vultures, and golden eagles.
Among mammals are marmots, argalis, Siberian ibex, snow leopards, wolves, and also the snow leopard.
The Ak-Sai Valley represents a high-altitude hilly plain with small elevation changes (up to 100-150 meters). The average height of the ridges in this area is 3200-3300 meters. Due to the lack of moisture, vegetation is not very abundant. Only in some places are there patches of tall grass, with hidden unevenness.
Additionally, in the valleys of the streams in the depressions, small marshy areas are sometimes found. These marshes are quite picturesque, where flocks of ruddy shelducks and sandpipers can be seen. In winter, such marshes become a "death trap" for argalis. Wolves, gathering in winter packs, drive the flock of argalis onto the ice of frozen marshes, where the "wolf work" begins...
There is a settlement of ancient humans from the Neolithic period here.
