Between 250 AD and 900 AD, the Maya engineered sky high temple-pyramids, ornate palaces and advanced hydraulic systems. They achieved these remarkable feats without the use of metal, pack animals or even the wheel. They were also legendary astronomers and timekeepers. While Europe languished in the Dark Ages, the Maya mapped the heavens, assigning great meaning to astrological phenomena, and making extraordinary predictions based on the stars and planets.