By popular request, here is some more information on Inca masonry and architecture.  The first is a quick, popular overview from the Ancient History Encyclopedia that describes Inca use of stones and bronze tools to shape rock.

I also found an older academic article on “Inca Stonemasonry” from Scientific American by University of California architect Jean-Pierre Protzen.  In the article, he gives a summary of the historiography of Inca technologies, and then goes on to describe his efforts to recreate Inca wall construction.  He provides a wealth of detail on the rocks used, quarries, and the tools used for transportation and structure.

As I mentioned in class, this is a topic rife with sophisticated-looking, poorly researched pseudo-scholarship.  I found an example (I won’t link to it) of a youtube video with over 900k views claiming that the Inca build their walls with bags of concrete…. historians beware!