Kyrgyzstan's most southerly region consists of two provinces, Osh and Batken, which make up the southern arm of the country that extends westwards south of Uzbekistan's Fergana Valley. The southern wall of the Fergana Valley forms a curious claw of Kyrgyz territory, although access to most of the mountain villages here comes from the Fergana Valley territory of Tajikistan or Uzbekistan.
The southern border with Tajikistan is demarcated by the high ridges of the Turkestan and Alay mountains, the most northern range of the Pamirs, while to the east is China's Xinjiang Province and the Great Game market town of Kashgar (Kashi), accessible from Kyrgyzstan across the border at Irkeshtam. The Batken region used to be part of Osh Province but was awarded provincial status in 1999 to become an oblast in its own right.
Osh Province has an area of 29,200km2 with a population of around 1,300,000 and a population density of 44.5 per km2, the highest in the country apart from Bishkek; neighbouring Batken is almost 17,000km2 in area with a total population of just 400,000, which is less than 24 people per km2. Together the two provinces make up just under a quarter of Kyrgyzstan's total land area. The vast majority of Kyrgyzstan's Uzbek minority live in Osh Province, where they are the majority ethnic group in many areas.
The beautiful valleys of the Turkestan ridge in particular offer superb trekking territory and the beautiful pyramid-shaped Ak-Suu peak (5359m), with its sheer 2km-high wall, is one of the world’s best extreme rock-climbing destinations.
This is not a particularly easy place to make your first Central Asian trek. You’ll need an Uzbek, Kyrgyz and Tajik visa to transit hassle free through these republics, as well as a spurious trekking permit. Moreover, some of the passes with Tajikistan are said to be mined. For the time being you are better off planning any trek in the region with an established trekking operator in Bishkek.