IntroductionFor centuries, people of all latitudes have been fascinated by the night sky. The unattainable stars, the Moon, the comets and all the events that happened in the sky, fired the imagination and became symbols of life and death, of war, of peace and of the passage of time and seasons. The movement of the stars served to establish the time of sowing and harvest, to prepare for the long winters and to try to discover the future and destiny, the eternal and unknown destiny of mankind. Three large human groups, the Maya, the Aztecs and the Zapotecs, populated the central and southeastern regions of Mexico long before Columbus' discovery of the continent. These ancient cultures developed a very complex knowledge of Astronomy and built a large number of structures intended to be used as observatories. They made precise measurements and kept records of all important events in the heavens. This article will explore some of the most important discoveries of these ancient astronomers and the precision of their building alignments. It will also establish the importance that astronomical knowledge had in their lives and society. Part I - The Maya The Maya culture occupied the southern part of Mexico and part of Central America. They were the only pre-Hispanic civilization with an advanced written language and a highly developed culture and body of knowledge that included the most advanced mathematics, art, architecture, and very accurate astronomy. The Maya developed sophisticated hydraulic systems, built extraordinary palaces, and designed and constructed pyramids and buildings believed to be observatories aligned with some celestial bodies and marked some of the most important astronomical events... middle of paper... ...heoCUs/99-01 -08.htm>.Ruggles, Clive LN "Ancient Astronomy: An Encyclopedia of Cosmologies and Myths." 2005. Google Books. December 2011 .Vail, Gabrielle and Christine. Hernandez. "Astronomers, scribes and priests." 2010. Google Books. .Welser-Sherrill, Leslie. Mayan astronomy. 2007. November 2011 .