Secrets of the Maya Underworld

S23, E12: Unlike great civilizations such as the Romans and the Egyptians, the Mayan empire did not arise from the banks of a mighty river. Then why did they populate Yucatan? The Maya believed that the freshwater pools dotted across the area were sacred portals to the underworld. They are indeed portals, but to an incredible underground labyrinthine system of rivers with amazing wildlife.