Oldonyo Lengai is an active volcano located in the Gregory Rift, south of Lake Natron within the Arusha Region of Tanzania. Part of the volcanic system of the East African Rift, it uniquely produces natrocarbonatite lava. The 1960 eruption of Ol Doinyo Lengai led to geological investigations that finally confirmed the view that carbonatite rock is derived from magma.

It is possible to walk across the crater floor. The ascent of Oldoinyo Lengai is demanding on account of the day time heat, lack of water, steep and unsuitable slopes of ash and crumbly rocks and considerable height gain. Normally you can start ascending to summit early in the morning and reach to summit at sunrise. Short and a warm jacket are suitable for ascent, also long trousers are good as the summit before dawn can be cold. Access route from the North West allows an early descent to be made from the summit in the morning shadow.

The Mountain frequently does minor eruptions and form cone like structures to its crater base.

While on the summit of Mountain Ol’doinyo Lengai one can sight clearly the Soda Lake Natron which accommodates and consist of good nesting sites for different bird species especially the Flamingos, pelicans and geese more than 350 different types are recorded to date.

Unlike others two highest Mountains, Lengai takes about six to seven hours to the summit crater. Also the Mountain is an ideal place for a working safari escort by the Maasai guides with weapons tourist can sight wild animals like olive baboon, velvet, monitor lizard, hyenas, lion, leopard, jackal, Grant’s gazelle, impala and zebra.

The nearby are the Maasai BOMAS that gives you a chance to interact with the indigenous learn their cultures, taboos and traditional.