Danescombe -

That's impressive! It gives me chills to see the diagram of those little men digging into the aquifer - not much attention to supporting beams and such, I'll bet! I've added a placemark to the folder that shows an enormous area with rows of qanats drilled roughly N/S. Thanks very much for the info...

I just found this today...a spectacular example of this system. Notice the older row on the left. This goes on for about 1.7 miles! Of course, these are modern and look like they were dug by machine, thus saving many lives!