You visit the Mahale Mountains National Park to meet some of Africa's last remaining wild chimpanzees. There are roughly 1000 individuals, and they have been habituated to humans, so you are able to track them and sometimes get surprisingly close.
Mahale Mountains is on the edge of Tanzania's Lake Tanganyika. As the name suggests, it is a mountainous region of rainforest. The main peak is Nkungwe (2,462m), and the range of altitude within the park means that a good number of species are found here.
Apart from the all-important chimpanzees there are eight other primate species, such as red colobus monkeys. You can also find leopard, warthog, and brush-tailed porcupines. The prolific birdlife includes the Crowned Eagle, Scaly Francolin, Crested Guinea Fowl, and Ross’s Turaco.
You can only access it by boat, so it really is a remote and little-visited spot.