It was common practice to strategically build ksour at the top of a hill on the edge of a rocky crag. From up there, they could keep a lookout for possible attacks and defend their fortified granary from above. Ksar Kerachfa, perched on this rather precarious cliff overlooking the land below, was a fine example of this. I found it amazing that the very reason that they located their ksar so high and out of reach from their invaders, was also the one that would cause them much hardship. It would certainly be a difficult and dangerous journey everytime they needed to lug their grain up there from the valleys for storage.