There is an ancient citadel in Peru, just to the northern outskirts of Cusco. Its name is Sacsayhuaman, and it is a true wonder of ancient engineering. Mainstream scholars argue that the Inca built the site in the 15 century under the ruler Pachacuti. However, the surrounding areas bear very different stonemasonry that points towards what many believe are two different civilizations. There are examples of megalithic stones that have been “pressed” together so that not even a single sheet of paper can fit between them. Then, there are stone walls built with a lesser quality, where stones seemed to have been just piled up one atop the other.
Some of the most beautiful stones at Sacsayhuaman were constructed without the use of mortar. Nevertheless, the stones remain in place almost as if they were constructed yesterday. Archeological studies have discovered pottery collections at Sacsayhuaman that date back to around 900 CE. However, as noted by many experts who disagree with the theory that the Inca built it, you cannot date this fortress by looking at pottery fragments.