What is the widest valley in the world?
It depends on the definition. The world's largest geological
depression is the Great Rift Valley running from Eritrea through
Ethiopia to Mozambique at 26,830 square miles; however, since it is
formed by plate tectonics rather than erosion, many do not consider
it a true valley. The world's largest valley formed by glaciers
and/or rivers (the conservative definition) is California's Central
Valley at 22,500 square miles.