Tanzania's outdoor landscape is anchored by two of the world's great wildlife experiences, but extends well beyond them. The Serengeti ecosystem's wildebeest migration — 1.5 million animals moving in a circuit roughly following the rains — is the largest terrestrial mammal migration on earth and can be witnessed from a vehicle or, increasingly, on foot with armed guides in designated walking areas. Kilimanjaro (5,895 metres) is the world's highest freestanding mountain and a multi-day high-altitude trail through five ecological zones from rainforest to arctic summit. The Selous Game Reserve (now Nyerere National Park) — larger than Switzerland — is Tanzania's walking safari country, where foot access in true wilderness delivers an entirely different quality of animal encounter than a vehicle. The Usambara Mountains in the northeast carry birding, tea estate walking, and highland forest at altitudes that make the Indian Ocean coast heat a distant memory. Tours by locals who know the landscape beyond the obvious map pins reveal the hidden gems. It really hits differently.