Summary In the tropical lowlands of Northern Colombia, a huge coal mine known as Cerrejón lies at the centre of the empty, forbidding outback. A team of scientists on an expedition in the mines uncover a number of animal bones, and among them is a bone they can't identify. A massive vertebra too large to belong to any jungle animal on record. What imposing creature could this giant backbone belong to? The lush rainforest of southwestern Cambodia's Cardamom Mountains stretches 4.4 million hectares and is so remote it can only be reached by helicopter. A conservation surveyor working in the area encounters a former soldier who is carrying ornate jars he had found in the mountains. The jars are tightly packed with bones and there are 40 others, balanced on ledges 300 feet above the jungle floor. Who or what did these bones belong to? In the Pacific country of Palau lies the small volcanic island of Peleliu. It can only be reached via airplane or a two and a half hour boat ride. A tourist taking photos in the jungle discovers a large, rusted metal object. It looks like a vehicle of some sort, but it's odd shape makes it difficult to identify. What is this thing? Southeast of Quito, Ecuador's capital, is the spectacular forest of the Unesco Sumaco Biosphere Reserve. The forest is home to some peculiar looking palm trees called the Socratea Exorrhiza. Characterized by their thin trunks that grow out of a series of above ground roots, it almost appears as if these trees are on stilts. When a biologist begins studying the forest for conservation purposes, he discovers something odd ¬- it looks like the trees are slowly moving in a new direction on a daily basis by themselves. Is that possible?

• Documentary