A yurt is a collapsible, fairly lightweight design, striking in its simplicity and functionality.  Apparently, the nomads had good knowledge of mathematics and physics, if they realized that the circular structure has a large capacity and can better resist winds.    The traditional Kyrgyz yurt was built without a single nail, using only materials that the nomads had on hand.  Willow, flexible, durable and supple, was chosen as the material for the round frame of the yurt.