The Yassy Zone occupies the valley of the same name, located near the city of Uzgen, 80 km from Osh. The Yassy River (Jazy) flows along the valley, and there is a road leading from Uzgen to the village of October 15. The area is characterized by magnificent climatic conditions — mild temperatures throughout the year, relatively low precipitation, and gentle winds that positively affect the human body, making this zone a potential climate resort. In the Yassy Valley, as well as in other gorges of the southwestern foothills of the Fergana Range, broadleaf nut forests spread, covering the extensive slopes with a green carpet of soft contours. Sometimes the river breaks through a dense green wall of mountain forest that separates it from the rest of the world. The gorge is home to many wild boars, as evidenced by numerous footprints. When traveling in these areas, one should exercise caution, as encountering a wild boar on the trail, especially during the breeding season, can be very dangerous. In the floodplain of the lower reaches of the Yassy River, near the city of Uzgen, there is the Yassy Hunting Reserve, covering an area of 5,000 hectares, established in 1975 to protect the floodplain reed and sea buckthorn thickets and marshy areas that serve as habitats for pheasants and wintering waterfowl.
Within the zone, many tributaries flow into the Yassy River, mainly from the right side. Among them, the largest are the rivers Zerger, Donguz-Suu, and Zindan-Suu. Zerger is over 50 km long and flows into the Yassy River near the city of Uzgen. In the valley of this river lies a village of the same name. Near the village of Donguz-Tuu ("boar mountains"), the Donguz gorge begins. A restless mountain stream winds through the gorge, flowing among the stones and entering the Yassy River from the right. Slopes of the foothills, covered with forest, approach it from both sides. On the gentle slopes, overgrown with fragrant grass, flocks of sheep lazily graze. The bottom of the gorge is sometimes covered with silt (moist areas). Around is a riot of greenery. Trees and shrubs intertwine closely, forming impenetrable thickets. In the interfluve of the lower reaches of the rivers Zindan-Suu and Donguz-Suu lies the Zindan coal deposit. Near the village of Myrza-Ake, one can see an interesting natural feature — a large grotto.
