It is hard to find any information other than scientific articles about the monkey island in Liberia. There is almost no information about people who have visited it, probably for the reason that it is in fact not a tourist site.
What it is: Monkey island is just a nickname for several islands about a 100km drive from Monrovia where chimpanzees from science labs were released out into the wild about twenty years ago. This was due to pressure from the growing number of people protesting on animal testing.
How to get there: From Broad Street in Monrovia you need to take a shared taxi (45mins/80cent) to the LRA building. From there you need to take another shared taxi (50mins/1,20$) to the airport. From the airport you hail down a motorcycle taxi and haggle hard for the last 35km on a bumpy dirt road, in my case I got it for 250 Liberian dollar which is 1,75$).
The boat ride: You can either go with a speedboat which feeds them mornings and afternoons for 30$ or you can ask one of the fishermen in a canoo like I did. I paid 10$ for a 30min ride at 1pm so that we made it there to the second feeding at 1.30pm.
Taking pictures: is not allowed. Probably because this, like I mentioned, is not a tourist attraction, but money always talks in Africa so you could ask the locals not to tell anyone if you want to take some pictures once the workers who are feeding the animals have gone.
The experience: was incredible. It was absolutely exhilarating watching them from a boat just a couple of meeters away, knowing that they can tear you apart if they would get angry and jump on your boat.
Be prepared if you are going there. Most people will not know where the place is, but you can find it on Google maps and just be persistent when trying to make the local fishermen take you. Chimpanzees are an endangered species with less than 100 000 of them left the world and everywhere else you would have to pay hundreds of dollars to see them in the wild. Seeing them walk around on two legs, stretching their hands out with humanlike expressions is something truly unique. I feel really lucky to have experienced it and if you read this I would urge you too to go see them while it is still possible.