Sepilok has a large nature reserve of million year old primary rainforest. It is run by conservationists who have a large program for rehabilitating orang-utan that have been displaced by the oil palm plantations. Kilometres upon kilometres of road is now line with these plantations and in some areas they go all the way to horizon. The rehabilitation at Sepilok is a great idea and gave us the opportunity to see the apes in their wild environment and at their HQ. I did a 7km trek in this forest with a English bloke I met. It was intense, the humidity was >95%. I looked like I had been in the shower. We were also attacked by numerous leeches. However it was very rewarding and the dense forest was more than impressive.