Africa's Great Rift Valley is the world's largest example of a rift valley. This photo looks west from the Butiaba escarpment, in Uganda, across Lake Albert to the escarpment of the Blue Mountains in the Democratic Republic of the Congo.
Other major rift valleys on the continents include the Rio Grande valley in New Mexico and the Lake Baikal rift valley in Siberia. But the greatest rift valleys are under the sea, running along the crest of the midocean ridges where the oceanic plates pull apart.
