If you look at the number of sites found in north, mid and south America, the list is unbelievable. there are many old civilizations like the Mayas, Incas, Olmecs, Caral Supe and Aztecs.
We will not describe all civilizations in detail, pages like Wikipedia do a great job on that. What we are interested in are the clues that lie in the middle of all that information. The parts that cannot be explained by the general view of that civilization.
One of the mail clues we think is the most obvious is the building technique. In the picture below we see the walls of Sacsayhuamán.
Here you see the massive rocks that are precisely stacked one onto the other one. Even if it would be possible to lift these massive blocks a few dozen times to cut away the rock and make it a perfect fit, this does not make sense for the time. Lifting and placing without any modern lifting equipment and not a single sing of a connection to lift such a heavy load, is still not even possible today.
Even more, the Spanish invaders only used a part of the rocks, also because most of them were just too heavy to handle. That is why it is still there.
And yes, Cusco was named that way because of the sound the stonework makes, but that is in our opinion just to duplicate the ancient stone masonary, like in the picture below. Stones that can be handled and even then, not a perfect finish.
The perfect finish is really something incredible. The picture bellow is not some kind of fake concrete or anything, it is actually the perfect match between the stones:
If we look at the famous Machu Pichu, we see something strange. The site has multiple building styles, see the picture below:
Simple stonework
Large sections of simple stonework
Large perfect fit building blocks
A double structure, below the ancient building blocks and on the top newer stones.
These different styles can explain the dating of the civilizations that used them in the latest periods. This is then written in the history books, but that does not make it true. Unless somebody can explain how these incredible walls of perfect matching stones were made, our conclusion is that it is not done by the same people that, in a later era built the simple walls on top or next to the ancient walls.
Even the building style of the oldest, the Caral Supe culture is like the common expected stonework of any old civilization. This leads us to think that for instance Sacsayhuamán is much older than the official period, the 14th AD century. Already in 2008 there was evidence foud that dates part of the site back to 1200 BC. And that is only the beginning according to the rules of logic thinking.