Lake Natron is a lake that stretches for about 60 km in the Great Rift Valley in northern Tanzania. Located at the base of the active volcano Ol Doinyo Lengai, it is of a desolate, enchanting, almost surreal beauty. The high sodium content and intense evaporation of the water, during the dry season, causes the proliferation of colonies of micro-organisms, including cyanobacteria, responsible for the distinctive red colouring. The lake varies in size, extent and depth depending on the seasons and rainfall patterns, so its colours also change from white to pink and from red to brown.
Its waters are dangerous because the very high percentage of sodium carbonate hydrate makes them caustic. The only being that can survive on its surface is the 'lesser flamingo', thanks to a protective horny layer on its legs and beak.
East Africa has 1.5-2.5 million lesser flamingos, accounting for three quarters of the world's total population. Most of this species nests in Lake Natron between August and October, ranking as the most important breeding site for lesser flamingos in the world. No wonder, then, that the shores of the lake were the location for the filming of the Walt Disney Pictures nature documentary 'The Mystery of the Pink Flamingos'.
Walks around the lake, streams and waterfalls, along the nearby escarpment, are a fantastic off-the-beaten-track adventure. Trekking enthusiasts, on the other hand, can try their hand at climbing the Ol Doinyo Lengai volcano. The trek is challenging, starts late in the evening and lasts all night (6 hours for the ascent and about 4 hours for the descent). The ascent of Ol Doinyo Lengai is tiring due to the scorching heat during the day and the lack of water. It climbs strictly straight up slippery slopes covered with ash and crumbly rocks, with a considerable difference in altitude. The ascent takes place at night to reach the summit at first light, when dawn offers the stupendous scenery of a dreamlike, desert-like, remote landscape. It is advisable to wear short but also long trousers and a warm jacket because the temperature can be cold at altitude. The access route from the north-west allows you to descend from the summit in the morning shade.
There are several Maasai Boma in the area, which give the opportunity to interact with the local people and get to know their customs and traditions.
Mount Ol Doinyo Lengai
The mountain rises south of Lake Natron, in the Great Rift Valley, right in the heart of Maasai land. The Maasai come from all over Tanzania and neighbouring Kenya to come and pray on the mountain that they consider sacred and to which they have given the name 'Ol Doinyo Lengai', which means 'Mountain of God'.
It is the only active volcano in Tanzania and also the only volcano, known in the world, to erupt natrocarbonatite, a rare type of volcanic rock rich in sodium, potassium and calcium carbonate, but low in silica. Because of this particular composition, the lava is extremely fluid and flows quickly: initially dark as oil, it rapidly clears due to chemical reactions with rainwater and moisture in the air, turning white and creating the illusion of a snowy summit. Lower temperatures, compared to silica lavas, result in a low incandescence unable to produce enough light to glow during the day. Another peculiarity, therefore, of the lava of Ol Doinyo Lengai is that it can only be visible at night.
The current cone of the volcano was formed about 15,000 years ago, but the depth and morphology have changed over the course of several eruptions. After the 2007 eruption, the active northern crater and the dormant southern crater merged together, creating a large caldera.
