Some of the recorded oral tradition stories tell that the circle was originally a reflecting pool constantly filled with water. It was used to watch the stars and other celestial bodies move across the heavens for scientific study purposes. The Inca had multiple pools and man-made canals or courses in many locations around Cusco and in the farmland surrounding it. This common historical knowledge adds to the belief that reflecting pools like this circle could definitely exists. The structure of this spot itself contains not only a sign of a surrounding wall to hold the water in but also a low opening or doorway that leads to a tunnel that could have been a drain so the pool did not overflow or could be changed when necessary. The pool itself could have been filled with rainwater quite easily according to the weather in the area.
There is no surviving indication of where the water came from if it was diverted to flow here from another source. After all, the Spanish deconstruction and all of the many years between then and now have changed the area quite considerably. Still, between November and March, which is the rainy season in that part of the world, the area stays quite wet.
The next location on the grand tour of the Cusco region lies to the north. The first thing you see is a gigantic boulder towering above your head and stretching sideways until it seems as big as a house. The so-called Chinkana stone contains carvings and three-dimensional sculpture of a wide variety of designs and pictures. Like many other things in the area, this was not created by the Inca. Older civilizations were responsible for this very unique feature.
With all of the unique structures and decorations that lie north of Cusco that are fashioned from the extremely hard andesite stone, one of the biggest questions that researchers and tourists alike have compassed down to the mechanics of actually mining it from the bedrock, shaping it, creating such perfect cubes in some places, and fitting them together so perfectly. The cultural aspects of the designs and structures, such as the carvings on the Chinkana stone and the reflecting pool used to study the night sky, are sometimes considered secondary to the architectural genius and stone cutting abilities that frequently defy explanation. Also, since it is generally accepted that the Inca had little to do with this, many people still question who it was that had this type of expertise.