Jungle trekking in the Gunung Leuser Nationalpark is an unforgetable experience. The Gunung Leuser Nationalpark is one of the last tropical rainforest systems on sumatra. Since 2004 it is counting to the UNESCO world heritage, covering an area up to 9000 km2 of the provinces Northsumatra and Aceh. It is the home for many different species of animals and plants and an important sanctuary for endangered species just like the sumatra-orangutan, the sumatra-tiger, the sumatra-elephant and the sumatra-rhino. The Gunung Leuser Nationalpark is probably one of the last places on earth, where orangutans can been seen in the wilderness. Beside of the orangutans there are many other species of monkeys like macaques, thomas leaf monkeys, black gibbons ( Siamang ) and white handed gibbons, snakes like pit vipers, pytons and cobras, lizards, honeybeers, birds like hornbills, the Great Argus and many more.