Seismic ready preinca

For stability, the walls were angled.  This is also the signature style of the ancient Inca. The small rock in between the big rocks was to ensure there would be movement and stability in times of earth quake. They already knew how to seismic upgrade their structures thousands of years ago. Very smart. Also, if you look closely, there were no cement to stick the rocks together. Rather, all the rocks were fit seamlessly. They did it by polishing the surfaces of each rock to ensure they fit perfectly.