This July 16, 2012 image released by Mexico's National Institute of Anthropology and History (INAH) on Monday Aug. 6, 2012, shows a human burial that was found next to what may have been a "sacred tree" at one edge of the plaza in Mexico City's Templo Mayor, the most sacred site of the Aztec capital. The National Institute of Anthropology and History said the find was the first of its kind, since the Aztecs were not know to use mass sacrifice or the reburial of bones as the customary ways to accompany the interment of a member of the ruling class. (AP Photo/INAH)