Places to see orangutans
Sumatra and Borneo are the only places in the world to see wild orangutans. The best place in Sumatra is probably Bukit Lawang in the rainforest at the edge of Gunung Leuser National Park. The rehabilitation centre is placed up river on the jungle side from the village. In good Indonesian easy-going-style, nothing is fenced off at the feeding platform, so you will get VERY close to the orangutans, so keep your distance to the big ones. It's also possible to do different treks through the jungle with a local guide to see the same orangutans, and maybe some others, in their natural habitat.
The iconic image of Borneo is a zoo like forest with big trees and an ecosystem teeming with life. Danum Valley gives you exactly that. Danum Valley is made up of 438 square kilometres of protected forest. It has the highest concentration of orangutans in the world, pygmy elephants, clouded leopards, and many more animals. Staying at the research centre is amazing because at the restaurant, you can converse with scientists that are studying the ecology of the forest. Very helpful if you have questions about the Bornean rainforest. There are many activities to keep you busy there from trekking to waterfalls to doing night safaris through the jungle. Bring some leech socks because it is a very healthy rainforest, and so that means lots of leeches! Go to the ridge observation tower for sunrise and watch the clouds burn off from the forest as the day starts. We guarantee it will be something you will never forget.
This is "the place" to see semi-wild orangutans in Sarawak. The centre is located 25 km outside Kuching and doesn't see that many visitors (compared to Sepilok in Sabah), not even in high tourist season (July - August). Feeding happens twice a day at the platform a couple of hundreds metres in the jungle, but there are no guaranties - the orangutans are semi-wild. Sometimes, they just hang around the park centre, especially mothers with their toddlers in tow, and then there's a pretty good chance to see them up close.