Bukit Lawang is a small tourist village on the bank of the Bahorok River in the North Sumatra province of Indonesia. Situated about 90 km north-west of Medan, along the banks of Bohorok River and on the outskirts of the tropical rainforest, Bukit Lawang is known for the largest animal sanctuary of Sumatran orangutan in 1973 a Swiss organization founded an orangutan rehabilitation centre in Bukit Lawang. The main purpose was to stop the decrease in the number of orangutans due to hunting, trading and deforestation as well as to rehabilitate the great apes released from captivity. The rangers taught the orangutans all the necessary skills to survive in the wild. After a period of quarantine, readjustment to the natural habitat and reintegration into the wild population, the orangutans were released back into the jungle.