We are all familiar with pre-Inca walls of Peru and other countries in that area. These walls are also worldwide, but there is little doubt the very best examples, in addition to being found at Giza, are in Peru. How were they built? One theory is that they must be concrete. Any experiment with building works shows that this is the quickest way these can be built. The idea of not being able to fit a piece of paper between the stones suggests they were not laid together perfectly, but that they formed that way.
Is this how polygonal pre-Inca walls were built?
Are the huge megalithic sites, really a type of geopolymer render?
Here is another video. It would seem that the so-called quarries are actually very very very odd sites!
What where the nubs for? Inca Walls
By Dr. Charles Kos.
Inca walls contain several protruding knobs, also seen on the granite casing stones of the Menkaura pyramid in Egypt. What if they were used for joining, like the knobs on Stonehenge for instance? Stonehengers may have been a very similar people! These were like huge lego blocks, perhaps! I am not totally happy with the joining theory to explain everything however. The most simple and perhaps most likely view is they were used for raising the stones, but there are other ideas...