Interesting story, but it gives me more questions than answers:

They say they dug up a wall protecting a spring from about 4000 years ago.

#1 If it was 26 feet high, why did you have to dig it up?
#2 If it were for a spring, considering the change all the digging suggested, then how would you know there was a spring there 4000 years ago.

#3 And most important: How does one move 4-5 ton boulders at that time to make a wall? I figured they had sharp sticks and maybe some cool sharp rocks at that point in time. How did they do it? And how dreadful must have been their defensive situation that such a thing would be considered necessary? It must have been a very brutal sort of life....