Mount Elgon

Declared on the Kenyan side in 1968 (its Ugandan counterpart followed in 1993), Mount Elgon is an extinct volcano with the largest intact caldera in the world, almost 8 km across. Its volcanic caves, Kitum among them, have been dug out and enlarged over generations by herds of elephants that walk into total darkness to prise mineral salt deposits off the rock walls with their tusks — behaviour documented in very few places anywhere.