In Guatemala, archaeologists identify an ancient site containing a series of unknown structures. Also, a lake full of jellyfish is studied on a remote South Pacific island and Argentinian researchers discover a complex that may have a dark past.

On the island of Sri Lanka, archaeologists investigate an ancient structure built on granite columns above the rain forest. Also, bizarre stone spheres are discovered in Costa Rica and the curious remains of a small man are found in Chiapas, Mexico.

On the island of Madagascar, paleontologists discover an intact fossil unlike any known animal, living or extinct. Also, bizarre stone spheres are discovered in Costa Rica and the curious remains of a small man are found in Chiapas, Mexico.

In the tropical lowlands of Northern Colombia, a team of scientists discover a massive, unidentified animal vertebra. Also, dozens of jars packed with bones are uncovered in Cambodia, and a strange rusted vehicle is found on the small island of Peleliu.

In the remote Cagayan Valley of the Philippines, archaeologists discover the remains of an ancient rhinoceros. Also, a Brazilian island is infested with thousands of deadly vipers, and researchers uncover shocking human remains deep in a Kenyan cave.

On the island of Pohnpei in Micronesia, explorers discover ancient structures hidden beneath dense vegetation. Also, a strange glowing forest is discovered in India and an immense tunnel system is investigated in the Brazilian jungle.

In the Australian rain forests of Lake Eacham, a scientist discovers a mysterious mouse-like creature that glows in the dark. Also, strange cylindrical tubes are uncovered in the forests of India and hundreds of human bones are found in a Belizean cave.

Off the coast of Tanzania, a puzzling site containing massive stone blocks is revealed on Kilwa Island. Also, the discovery of giant animal bones baffle researchers in Australia and 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. Also, a researcher finds two unknown animal skulls in Vietnam and 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. Also, strange grass covered domes are investigated in the Philippines and archaeologists uncover carved stone figures on the Hawaiian island of Kauai.