Secrets in the Jungle

Off the coast of Tanzania, a puzzling site containing massive stone blocks is revealed on Kilwa Island; the discovery of giant animal bones baffle researchers in Australia; hundreds of human bones are uncovered in a Guatemalan rain forest.

On the volcanic island of Kolombagara, explorers uncover a mysterious man-made cave in the dense jungle; a researcher finds two unknown animal skulls in Vietnam; human remains are discovered in a narrow chamber of a South African cave system.

In the jungles of southern Mexico, a rancher discovers dozens of skulls and bones on a cave floor; strange grass-covered domes are investigated in the Philippines; archaeologists uncover carved stone figures on the Hawaiian island of Kauai.