Fergana is one of the most ancient cultural oases of Central Asia. The Fergana Valley is an intermountain depression in Central Asia, between the mountain systems of the Tien-Shan in the north and the Gissar-Alai in the south. The valley is approximately 300 km long; its width is 60-140 km. The Fergana Valley is rich in natural resources, including gold, oil, copper, etc. The Sir-Darya, one of the great rivers of Central Asia, runs across the valley. It is fed by more than 70 mountain streams. Thus, Fergana is most densely populated region of Uzbekistan.