Sumatra, in Indonesia, is a natural reserve and jungle land with acres and acres of forests, and forests, and a large diversity of natural world, avian life, flora and fauna. And, this facet of Sumatra is an eye-catching preference for tourists, especially those who worship nature, and would like to use up time in the wilds while on a holiday. One such striking spot that attracts people is the Bohorok Orang-utan Viewing Centre. Situated just external Bukit Lawang Gunung Leuser National Park, in Sumatra, the Bohorok Orang-utan Viewing Centre is about 90 kms from Medan. The Bohorok Orang-utan Viewing Centre is a well-known rehabilitation centre that was established in 1973, by two Swiss zoologists, Regina Frey and Monica Boerner. The orangutans of Sumatra are an in danger of extinction, with loss of habitat, and poaching pushing them towards annihilation.