Ancient irrigation systems are often the ignored wonders of the world. My favourite is the Zarch Qanat, which is about 3000 years old and has a tunnel into the

Ancient irrigation systems are often the ignored wonders of the world. My favourite is the Zarch Qanat, which is about 3000 years old and has a tunnel into the water table which is about 71 kilometres long with over 2000 vertical shafts into the tunnel. http://www.livius.org/q/qanat/qanat.html http://www.livius.org/q/qanat/qanat.html http://en.wikipedia.org/wiki/Traditional_water_sources_of_Persian_antiquity http://en.wikipedia.org/wiki/Traditional_water_sources_of_Pe...