The Yunnan Province in China marks the first leg in the 2,700-mile journey of the Mekong River. Fed by countless tributaries and glacial meltwater, it traverses the land it helped shape, giving sustenance to the region's exotic, and often endangered, wildlife. Join us as we map the path of this mightiest of rivers.

In the Laos chapter of its journey, the Mekong River cuts through ancient tropical forests teeming with wildlife. Discover flamboyant peacocks, stump-tailed macaques, and endangered black-crested gibbons, of which there are only 2,000 left in the wild. Follow the flow of this mighty river through a little-seen corner of Asia.

As the Mekong River snakes its way through Thailand, touching the borders of Burma and Laos, it hits a mountainous region of dense forest: the Golden Triangle. Home to 10,000 exotic plant species, it also serves up a rich mix of wildlife, from rare langurs to Asian elephants and majestic cranes.

In central Laos, the Xiangkhouang Plateau is a landscape characterized by green mountains, rugged karst formations, and verdant valleys, with the Mekong River at its heart. It's also home to primates like red-shanked doucs, as well as more mysterious inhabitants in the region's vast underground caves--some never before seen on film.