If you would like to see the evidences of ancient civilizations and their technologies you should come to Cusco, the city that placed around 3450 meters (11300 ft.) high on the Andean mountain.
According to an Inca legend, Cusco was built by Sapa Inca Pachacuti, the Incan King who changed the Kingdom to the great empire in 13 century AD and Cusco became a capital. But in the same Incan legends the capital of Incan empire was built on the ruins of other previous old unknown kingdom.
Modern archaeologist discovered presence of old cultures dated in 10-12 centuries AD and no evidence of high construction techniques which were used in Cusco for construction monumental walls in polygonal masonry style.
It’s not hard to note that there are two deferent style of walls construction in Cusco. The first one represented by buildings consisted from small rock debris with sharp and chipped edges. These stones were connected by clay and mud. Inca could built in this manner as they have this study, skills and tools for letting them construct buildings in this no “high standard” style. The second one is polished stones surface of different sizes with straight edges with no connected materials. It’s known as polygonal masonry architecture style. It’s a great mystery how ancients made the colossal walls and buildings without using connected materials, concrete, building crane and even wheel. Note that Cusco located on tectonically active region and after 1650 and 1950 earthquakes polygonal masonry kept well in the city.
In present time one can see several restoration sites in Cusco. No need to know this places because they clear to see by the own eyes because of stones were connected by concrete in no sense manner without edges connection as pre-Incan civilizations used to do.
In 1950 earthquake the Santo Domingo cathedral was damaged, during the restoration work ancient retaining walls were found in perfect shaped surface represented engineering art of ancient architects. So Qurikancha walls were exposed presented one of the most intrigue mystery of the city.
On the pictures made by world-pyramids team during the research trip you can clear to see these two different construction techniques: primitive Incan stone debris works and polygonal walls with perfect quality construction style from prehistoric time. And restoration works by modern archaeologies which tried to imitate polygonal masonry but failed.
Cusco city is still has a lot of secrets which are waited to be revealed!