The Persian Qanat

For millennia, Iran's arid regions have drunk through hidden veins: qanats tap aquifers at the heads of valleys and lead water by gravity through underground tunnels, often across many kilometres. Eleven exemplary qanats — complete with rest areas for workers, reservoirs and watermills — represent the system, still governed by traditional communal management that shares water fairly and sustainably. The Persian Qanat was inscribed as UNESCO World Heritage in 2016.