The Qanats of Gonabad
How did Iron Age well-diggers, working by lamplight with hand picks and a rope windlass, sink a shaft roughly 300 metres into the desert and then drive a tunnel some 33 kilometres back to the surface — holding a gradient of a fraction of a percent the whole way, underground, with no way to see where they were going?
c. 700-500 BCE, Achaemenid era (traditionally attributed to a legendary king centuries earlier) · Gonabad, Razavi Khorasan Province, IranAdded September 2026