Summary In the northwestern Pacific, near the shore of Pohnpei in the Federated States of Micronesia is a lush green island that holds a massive, mysterious structure hidden beneath dense vegetation. When a tourist sets out to explore the island, they notice that it isn't just one structure, but 99 islets near each other. What was this place? On the northern coast of the island of New Guinea, an unsettling sight is revealed on a steep hillside beneath the canopy - scattered bits of charred metal and broken glass lead to what resembles the tail section of a plane, decaying in the humid climate. Whose plane is this? And where did it come from? India's Western Ghats, located 2.5 hours from Mumbai, is a mountain chain that contains some of the best examples of tropical evergreen forests anywhere in the world. Hikers exploring the forest at night stumble upon something astounding - hundreds of glowing green lights on the forest floor and in the trees. What is causing this strange phenomenon? In western Brazil, near the Bolivian border, a scientist working on a geological survey in a forested area comes across an unusual hole in some rocks. Exploring further, he discovers that the hole is actually the entrance to an enormous underground tunnel system stretching almost 2000 feet deep into the hill. What is this incredible place?

• Documentary