The discovery of strange giant stone heads in the Mexican jungle leads archaeologists to La Venta, the lost capital city of the Olmec, and new investigations real evidence that the secret knowledge of these mysterious people changed life in the Americas forever.

Deep in the jungle, the lost city of Tikal holds the dark secrets of the Maya, and now, a new investigation uncovers how it grew into a megacity home to 100,000 people, and why it was mysteriously abandoned.