Qanat

A qanāt (قناة, Persian: قنات) is one of a series of well-like vertical shafts, connected by gently sloping tunnels. Qanāts create a reliable supply of water for human settlements and irrigation in hot, arid, and semi-arid climates. The qanat technology is known to have been developed by the Persian people sometime in the early 1st millen...
Found on http://en.wikipedia.org/wiki/Qanat

qanat

underground tunnel for carrying irrigation water
Found on http://phrontistery.info/q.html
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