Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. The Fergana Valley or Farghana Valley, is a region in Central Asia spreading across eastern Uzbekistan, Kyrgyzstan and Tajikistan. The most important part of the province is a rich and fertile valley, in an altitude of 1200 to 1,500 ft (457 m) (400 to 500 m), opening towards the southwest. The valley owes its fertility to two rivers, the Naryn and the Kara Darya, which unite in the valley, near Namangan, to form the Syr Darya. Numerous other tributaries of these rivers exist in the valley including the Sokh River. The streams, and their numerous mountain effluents, not only supply water for irrigation, but also bring down vast quantities of sand, which is deposited alongside their courses, more especially alongside the Syr Darya where it cuts its way through the Khojent-Ajar ridge, forming there the Karakchikum. This expanse of moving sands, covering an area of 750 mi², under the influence of south- west winds, encroaches upon the agricultural districts. The Fergana Valley is a very big open wide space that is very good for farming.