Boysun is a land of deep rocky canyons and famous karst caves. The vertical walls of the 10-20 meters wide canyons cut out by the Machai-sai and Shurob-sai reach a height of several hundred meters. Usually the roads to the far mountain kishlaks run along the bottom of such canyons. The abundant spring rains quite often cause destructive mudflows in the mountains, and mountain УsaiФ can easily carry heavy stone blocks up to several tons in weight. Such mudflows crush everything crossing their path: bridges, roads and communication lines marooning the mountain kishlaks.
         The Boysuntog Mountains contain a lot of unique caves, used in the past ritual for dwelling, economic and purposes. The famous cave of Sezam in Boysun featured in the Uzbek-Indian film УAli-baba and the forty thievesФ. The Uralsky cave is 565 m in depth and 2500 m in length. The system of УFestival Ц LedopadnyФ caves is 625 m in depth and 3000 m in length; the cave of УBoi-bulokФ measures 1160 m by 14270 m; that of Zaidman Ц 506 m by 1500 m. Very popular among speleologists is one of the deepest caves of Central Asia Ц the cave of УBoi-bulokФ with elevation changes of 1415 m, located near the kishlak of Kurgancha. It has two holes 27 m and 20 m deep and several shelves; the remaining part is formed by a narrow meander.