Overlooking Lake Natron and the bushland of Kenya to the north, Ol Donyo Lengai, which means ‘the home of God’ in Masaai, is an active volcano and one of Tanzania’s most spectacular and undiscovered climbs. The volcano erupts sporadically, sending small streams of grey lava down the crater rim and spitting hot ash high into the air. The climb, undertaken overnight so hikers can experience sunrise over the Rift Valley escarpment, is highly challenging.