Subscribe to watch full natural history and science documentaries! A new documentary is uploaded every week.

Facebook: www.facebook.com/thesecretsofnature
Twitter: twitter.com/NatureUniversum

Southeast Asia at its best. 85% of the country is untouched nature, widespread forests, steep mountains and wide river valleys, but also cool high plateaus and savannahs. The primeval forests support a fauna like something out of a fairy tale, with elephants, tigers, leopards, and some of the rarest animal species on the planet. Species never seen by humans are discovered at regular intervals. In recent decades, the few large mammals to be described for the first time were all found in Indochina and experts assume that most of them are at home in Laos: wild oxen such as the saola and kuprey or the truong son munjak. No outsider has ever seen a living specimen of the latter; its existence is only known indirectly, through skeletons, horns and bag that are occasionally found in remote villages. And there is the Mekong, one of the last untamed rivers on Earth. Fed by hundreds of tributaries, it is one of the richest freshwater systems on the planet, comparable only with the Congo or Amazon. This is where the Mekong catfish lives. At 3 meters long and weighing in at 300 kilograms, this monster must be the largest freshwater fish on earth.