Categories Breaking News Rare Calculators Dating Back to the Incas Found in Peru Post author By Tajirul.Haque Post date July 1, 2014 th century. This makes the present day findings even more important. ]]> Tags Khipu, mysteries of the Inca civilization, Quipu ← Story of the Largest Pre-Historic Mound in Europe: Silbury Hill → Ancient Chines Levees Caused Environmental Change