Pumapunku - an amazing ancient site in Bolivia truly defies all logic. We thought Egyptian pyramids were a impossible feat, but imagine an ancient man carving stones with precision as if they were on an assembly line in a way that only a diamond cutter could do today?
The best date range for its age so far is that it was erect somewhere in the 536-600 AD range. The red sandstone blocks were brought uphill from Lake Titicaca about 10 km away (6 miles). The carved stones were done in such a way as to be interlocking. Joints were so precise, even a razor cannot be placed between them.
It was believed these beautiful buildings drew pilgrims for spiritual sanctuary. Yet again, we have an Indian group who went missing all of a sudden, like other tribes in the Southwestern US in the past. Was it drought? Lack of resources? Natural disaster?
Even much of the art seems to have strange insights into other races including ancient alien visitors -
Is it possible man had a passionate mission for his perceived god(s), higher technology than we thought, or help from outside our planet?
Another one of those mysteries we can't ever know because there is no one from that time to tell us. Oh yes, they leave clues behind, but with thousands of years between us, those clues are scattered, ruined, missing, broken, or otherwise interrupted by floods, earthquakes, and pillaging. There are a lot of interpretations we can put on these places. I, for one, see this piece of art (above) and compare it to the interlocking carved stone pieces and they seem to reflect each other. Another person viewing it, might see something quite different. I am always intrigued by artistic interpretation, but like Van Gogh, we certainly can't take it too literally.
Still, I cannot by any stretch of my imagination come up with a scenario for how that stone was carved. That is truly one of the greatest man-made mysteries of all time.