Saksaywaman
First built around 1100 AD, the stones of Saksaywaman in Peru are so closely spaced that a single piece of paper will not fit between many of the stones. This precision, combined with the rounded corners of the blocks and the variety of their shape have puzzled scientists for decades. What’s more, the wall is located at an altitude of 12,142 ft – which is roughly the same height as some of the highest peaks in The Rockies. The precision, combined with the rounded corners of the blocks and the variety of their interlocking shapes have puzzled scientists for decades.