In the southwest of Rwanda, Nyungwe Forest National Park is an enormous tropical forest with a high canopy. Access is easy, but start on one of the guided walking or hiking trails and you'll rapidly realise just how big it is. Tall old mahoganies, ebonies and giant tree ferns tower above you, whilst orchids and other epiphytes cling to every branch. Brightly coloured birds flit around, butterflies are everywhere, and walking quietly you may encounter larger forest residents.

Nyungwe Forest is, in fact, the largest swathe of montane forest left in East or Central Africa. It harbours about 275 different birds, hundreds of butterflies and orchids, and over 75 different species of mammals - including 13 primates (about a quarter of all Africa's primates).