Most of the dry lands in Iran are water supplied by a system of Qanats. A qanat is an underground canal, which with a mild slope transfers the underground water to the lower grounds. Depending on the slope of the ground, a qanat length can vary and it may be as long as tens of kilometers. The file includes eleven selected qanats each of which being unique in its architecture, depth, length, water content and other technical specs. The longest qanat in Iran is 63 km with 2115 wells in its path. The deepest well in the path of a qanat is 350 m, which has survived for centuries in spite of earthquakes and other natural disasters. The most surprising qanat in Iran is the Moon qanat, which was made 800 years ago in two floors.