Qanats are a fascinating engineering feat requiring a precise slope of 1:1000 or less, built over 2000 years ago. It is really amazing what these ancient civili

Qanats are a fascinating engineering feat requiring a precise slope of 1:1000 or less, built over 2000 years ago. It is really amazing what these ancient civilisations built with the technology available. ETA: Also one of the few scrabble words with a "q" but no "u" :-)