Mexico is one of the world's greatest resource countries -gold, silver, copper, rain forest, and archeological ruins. Teotihuacan is one of Mexico's greatest legacies and mysteries left for us to comprehend. The unknown builders of this site had an advanced understanding of geometry and astronomy, all to be found staring at us in stone. Today, thousands of Mexico's people still celebrate the sunrise at the vernal equinox on top of the Pyramid of the Sun at Teotihuacan.