The planet’s largest terrestrial geographical feature, the Great Rift Valley stretches across 6000km from western Arabia to the Lower Zambezi region of Mozambique. More than 1km deep in parts, it follows a fault line associated with tectonic plate activity, the phenomenon which, 200 million years ago, caused the vast landmass of Gondwanaland – which comprised most of today’s Southern Hemisphere – to start splitting up into our present-day continents, and which, more recently, wrenched Madagascar and Arabia from mainland Africa.
Africa’s Rift Valley started to form around 25 million years ago, and its subsequent expansion has been accompanied by significant volcanic activity. Indeed, the valley floor is studded with active and dormant volcanoes, among them Ethiopia’s Mount Fantalle and Erta Ale. In addition, many other major peaks outside of the valley are volcanic by-products of the rifting process – among them snowcapped mounts Kilimanjaro and Kenya.
The Eritrean–Ethiopian portion of the Rift Valley runs from the Red Sea to Lake Turkana on the Kenyan border. In the north, it forms the inhospitable Danakil Desert, while further south, the region coursed through by the Awash River has yielded several of the world’s oldest hominid fossils, suggesting that much of human evolution took place there. South of the Awash, a damper stretch of the Rift Valley bisects the Ethiopian Highlands, its floor studded with a string of beautiful lakes starting with Ziway in the north and running all the way south to Turkana. Eventually – several million years from now – the Rift Valley will most likely flood completely, splitting Africa into two discrete landmasses.