The Borneo rainforest is 130 million years old, making it the oldest rainforest in the world and 70 million years older than the Amazon rainforest. Borneo is very rich in biodiversity compared to many other areas, there are about 15,000 species of flowering plants with 3,000 species of trees (267 species are dipterocarps), 221 species of terrestrial mammals and 420 species of resident birds in Borneo. It is also the centre of evolution and radiation of many endemic species of plants and animals. Subject to mass deforestation, the remaining Borneo rainforest is one of the only remaining natural habitat for the endangered Bornean Orangutan. It is also an important refuge for many endemic forest species, as the Asian Elephant, the Sumatran Rhinoceros, the Bornean Clouded Leopard, and the Dayak Fruit Bat. It is one of the most biodiverse places on earth. The World Wildlife Fund has stated that 361 animal and plant species have been discovered in Borneo since 1996, underscoring its unparalleled biodiversity. In the 18 month period from July 2005 until December 2006, another 52 new species were found. BBC Wildlife adventure series following now a team of explorers in the heart of the tropical island of Borneo, a lost world of unexplored jungle protected by a fortress of impenetrable mountains. Borneo has a breathtaking landscape with a chain of remote, steep mountains and gorges running down the centre of the country. Expedition Borneo looks at the huge expanse of wilderness, where only a few tribes live and which is teeming with rare and previously undiscovered wildlife. A team of biologists, anthropologists and climbers explore this new terrain in this fascinating series from the BBC Natural History Unit. Their aim is to find evidence that will help the area to be preserved forever. 沿着婆罗洲中央脊柱往下是一系列陡峭的山脉、深邃的峡谷和高原。这一无法穿越的地带让婆罗洲不受外界的危害，能在这片荒野生存的唯一人类只有一些偏远的部落。如今，一个由生物学家、人类学家和登山者组成小组开始探索这个另一惊异的世界，以及生活于此的人类。他们的目的何在？发现稀有动物，帮助创建一个新的巨大的保留地，地球上最后一个伟大的“失落世界”。