List 5 acheivements of the mayans

The building of temples and great cities without modern machinery, using astronomy to predict astrological cycles and plant crops and using their language to communicate and measure time are some of the Mayans most notable achievements. During a 600-year period of time, which was from 300 A. D. until 900 A. D., the Mayans made many great achievements in science, communications, engineering and agriculture.