Every Then & Theory plate comes from a true story, and this card tells the one behind yours.

The Then & Theory team

Water by gravity

A channel of water runs down a shaded street of awnings and stairs. The plate names no town. In the dry country of Iran, qanats have carried water to towns and farms for centuries, some for millennia. A qanat taps groundwater at the head of a valley through a deep mother well, then carries it along a gently sloping tunnel, by gravity alone, often for many kilometres. Shafts along the way let diggers lift out spoil and let air in, and from above they look like a line of craters. Where the tunnel reaches daylight, channels share out the water.

Sources

1. UNESCO World Heritage Centre, “The Persian Qanat”