The Alai Valley is a wide high mountain valley in the Osh region in the extreme south of the Central Asian Republic of Kyrgyzstan. It is located in the two districts of Alai and Chong-Alai and stretches for a total of 180 km from east to west between the Alai Mountains in Kyrgyzstan in the north and the Pamir Trans-alai chain with the 7134 m high Lenin Peak in Tajikistan in South.
A branch of the Silk Road once ran through the valley. Now, the valley is popular with mountaineering tourists of various levels, as the relatively easy +7000 Peak Lenin is widely accessed by the Kyrgyz side of the valley. A base camp south of Sary-Moghul is accessible during the summer months. Trekking tours of the Alay Mountains overlooking the valley can be arranged upon arrival for the non-hard-core mountaineer, and more elaborate cross-mountain tours to the Alay Valley from the Kyrgyz Fergana.
The park includes the gorges of the Ala-Archa River and its tributaries and the surrounding mountains with around 50 peaks and around 20 large and small glaciers. The glaciated area covers 33 km² (around 17% of the total area) and has shrunk by 17.9% since 1964. The glacier thickness has also decreased since the 1970s. Smaller mountain rivers that flow into the Ala-Archa River are fed by the meltwater from these glaciers.
The valley is traversed in almost its entire length, with the exception of the eastern 30 km, on its northern flank by the Kyzylsuu, which rises east of Sarytash in the Alai Mountains and flows off to the west. Especially when the snow melts, it is fed by numerous tributaries and spreads over its wide bed of debris. It leaves the valley at the Karamyk pass through a gorge to Tajikistan.
The climate in the valley is inhospitable, with long and very cold winters. This, the soils, which are mostly unsuitable for arable farming, and the remoteness from the traffic point of view explain the extensive lack of permanent settlements. The district of Chong-Alai, which encompasses the entire western valley, has fewer than 25,000 inhabitants, scattered in mostly small settlements grouped into three communities on the southern slopes of the Alai Mountains or in the northern wind-protected side valleys. In the summer months, shepherds from other areas, including Tajikistan, come with their families and herds into the valley and the side mountain slopes.