>So if they are 15 centuries apart in
>construction date why was this mode
>of construction so rare?

Well, when one quarries good quality rock by trenching the larger the blocks generally the greater the yield one gets from the quarry. It's a trade off between quarry volume, manpower, distance from construction site, ease of transport, rock quality, timetable limitations, cost, etc. etc. etc. etc. All these variable change from one project to the next and sometimes they all come together just right to allow ashlar/cyclopean as a reasonable solution. You do realize that the blocks in Khafre's Valley don't weight anything remotely close to the fringes' 200 tons right? The AE did use larger blocks in some of their other constructions to various degrees.

Archae Solenhofen (solenhofen@hotmail.com)