Bwindi Impenetrable National Park, covering 32,092 hectares, is one of the largest areas in East Africa which still has Afromontane lowland forest extending to well within the montane forest belt. Located on the eastern edge of the Albertine Rift Valley and believed to be a Pleistocene refugium, the property is a biodiversity hotspot with possibly the greatest number of tree species for its altitude in East Africa. It is also host to a rich fauna including a number of endemic butterflies and one of the richest mammalian assemblages in Africa.