Oldoinyo Lengai; meaning 'Mountain of God' in Maasai language, is a volcano located in the north of Tanzania and is part of the volcanic system of the Great Rift Valley in Eastern Africa . It is located in the eastern Rift Valley , south of both Lake Natron and Kenya . Oldoinyo Lengai is of particular interest to geologists because it is the world's only active volcano that erupts natrocarbonatite lava, a unique occurrence of volcanic carbonatite. The mountain is also the only active volcano in this part of the East African Rift Valley, though there are many older extinct volcanoes in this region. Oldoinyo Lengai rises about 2000 metres above the Rift Valley floor to a height of approximately 2886 metres. A few older extinct carbonatite volcanoes are located nearby, including Homa Mountain .