Simon Reeve leads a team of journalists on a spectacular journey down east Africa's Rift Valley.
From the tiny country of Djibouti, which is the centre of America's military presence in Africa, to the wide open plains of Kenya, the team encounter awe-inspiring landscapes, rich culture and amazing wildlife.
In Ethiopia, even in the green and fertile Rift, people are still going hungry, and in northern Kenya global climate change is driving tribes to war over water and resources. In the foothills of Mount Kilimanjaro, Masai warriors are running a project to protect the country's lions.
The Rift Valley in Africa is described in detail here.