Subsequent generations, marvelling at the pyramids, have often wondered how they can have been built. The ancient Egyptians, without the benefit of wheels, pulleys or even scaffolding, somehow move vast blocks of stone into their exact positions at the top of very high monuments.

Their largest creation, the Great Pyramid at giza, consists of some 2,300,000 blocks of stone weighing on average 2.5 tons. The top of the pyramid, when first built, is nearly 150 metres above ground level. How is it done?

No one knows for sure. But it seems that the great slabs are inched laboriously along a specially prepared road, towards the base of the pyramid, by means of levers and perhaps rollers. When the first level is complete, the road is tilted up slightly - by building it up into an inclined ramp - and the next stones are edged slowly along this. Beyond a certain point the ramp cannot become steeper. As the pyramid rises, the ramp merely becomes longer - like a road up a gentle but lengthy hill. When the pyramid is complete, the road is demolished.

A similar method seems to have been used 1000 years later for Karnak and Luxor, the great temples of Thebes.

It seems impossible to imagine how the vast cross beams and ceiling stones of the Egyptian temples at Karnak and luxor should have been settled into place without any lifting gear. But the method is the same as for the pyramids, except that a temple is not solid.

Each stone slab is edged up an earth ramp and settled into position. This means that the growing temple becomes part of the ramp. When the structure is finally complete, the entire space between and around the columns is densely packed with earth and rubble. The topping out ceremony becomes one of burrowing out. The builders' last task is to excavate the temple's interior.