Lake Natron got its name due to the mixture of salt and minerals, called natron, which are revealed when the water’s level decreases. Natron is a compound that occurs naturally, comes from volcanic ash, and is mainly consisted of sodium bicarbonate and sodium carbonate.
Located close to the Kenyan border, Lake Natron is fed by some springs that are rich in minerals, making the lake highly alkaline, reaching a pH of 9 to 10.5. To put things in perspective, sea water has a pH between about 7 and 9. The temperature of the shallow lake’s water can reach 140 degrees Fahrenheit and is salty enough to poison most animals. All these characteristics, make Lake Natron the deadliest in the country. The crust created by the alkali salt sometimes gives the lake a red or pink hue, or even orange in the more shallow parts, by the microorganisms that live there.
Despite all of this, the lake remains one of the main breeding grounds for lesser flamingos, a species whose status of ‘near threatened’ is a direct consequence of its dependence on Lake Natron for breeding purposes. During periods when there isn’t much rain, the lake’s water level decreases, revealing salt islands, on which birds build nests. The blue-green algae that grow in the water, in turn, feed on the birds’ nests. Animals that die in the lake are turned into statues, through calcification.
No one really knows how these animals die. On theory, expressed by photographer Nick Brandt, is that the reflective nature of the surface of the water is confusing to the birds who crash into the lake. The extreme sodium bicarbonate content preserve them perfectly, making them look like statues. Brandt discovered the calcified creatures when he went on an exhibition to the lake, and could not help but photograph the statue-like birds. With the exception of a species of fish that has evolved to survive in the Lake Natron’s deadly water, no other species survives near it.
This spectacular area sits just north east of the Ngorongoro Crater and forms part of Africa's immense Great Rift Valley. Nestled between rolling volcanic hills and deep craters, Lake Natron sits at the lowest point of the rift valley – 600m above sea level – and is probably the world's most caustic body of water.
This area is hot and often very dry and dusty – so certainly for the more intrepid traveller. But for those who do choose to visit Natron, they are rewarded with an area that is far off the beaten track and sees relatively little tourism. It is also some of the most dramatic scenery which can be seen in Tanzania and the journey here is worth it for the views alone.
Activities in the Lake Natron area focus mainly on walks. You can walk out across the baked mud to the shores of the great soda lake itself, in which algae and zooplankton thrive – which in turn attract the flamingos that line the lake's shore. Look back at the mesmerising view of Oldoinyo Lengai – standing tall in amongst rolling hills and flat plains. Its ash-grey colour and smoking top remind you that this is still very much active. This walk is best done in the very early morning or late afternoon out of the heat of the day.
Whilst here, take the chance to walk up to the Engero Sero Waterfalls. This walk winds up through a shady gorge (very welcome in the heat) between steep cliffs. There's a bit of gentle scrambling involved, and you'll also cross the river a few of times. However, after a few hours you'll reach a beautiful natural swimming pool surrounded by steep rock walls – showered by cascades of spring-water and overlooked by palm trees. We didn't mind getting a little wet, and so loved this walk and the swim at the bottom of falls.
The more adventurous (or foolhardy?) might like to try and climb Oldoinyo Lengai. This climb usually starts at midnight, and you climb for around six hours, through the night, to reach the spectacular views of the top by sunrise. Anyone embarking on this walk must understand that it is a very tough climb, and that as this is an active volcano, so high risks are involved. Oldoinyo Lengai is not a climb to take lightly, or without thinking seriously about the possible consequences.