Lake Eyasi & Lake Natron

The lake itself e a shallow, alkaline salt lake set against the dramatic escarpment of the Eyasi Rift e is beautiful in the way of remote and neglected places. Doum palms line its shores. The water shifts from pale silver to deep blue depending on the light and the season, and in the wet season the flamingos arrive in their pink thousands along its margins. But the lake is really a setting, not a destination. What makes Eyasi extraordinary is the human presence on its southern and southwestern shores.

De Hadzabe e also known as the Hadza e are widely regarded as one of the oldest continuously inhabited human populations on Earth. Genetic and archaeological evidence places their ancestors in this Oost-Afrikan region for hundreds of thousands of years, and the click-consonant language they speak bears ancient resemblances to the click languages of the Khoisan peoples of southern Afrika e a linguistic echo of a time, perhaps 100,000 years ago, when human populations were far less geographically separated. Today, approximately 1,000 to 1,300 Hadzabe individuals remain, living in small, fluid bands around the shores of Lake Eyasi and in the adjacent Yaida Valley.

They live as their ancestors lived: hunting game with hand-crafted bows of animal sinew and arrows tipped with iron points traded from their Datoga neighbours, gathering wild fruits, tubers, baobab seeds, and honey from the doum palms, and moving camp when the resources of one area are depleted. There is no agriculture, no livestock, no accumulation of property, and no concept of permanent land ownership e only the bush, the season, and the hunt. The Hadzabe have no single leader. Decisions are made by consensus, and no adult has authority over any other. They are monogamous, marry within the tribe, keep no records of births or ages, and hold an animist belief system in which the gods of the river, the fire, the trees, the sun, and the spirits of animals are all living presences. It is, by any measure, one of the most remarkable and most fragile human cultures remaining on Earth.

Naast hen, aan de rand van het meer, wonen de Datoga e a Nilotic people of a completely different tradition. The Datoga are semi-nomadic pastoralists of great pride and extraordinary skill: specifically, they are blacksmiths of remarkable ability, forging iron tools and weapons from scrap metal using bellows, fire, and techniques passed down through generations. The relationship between the Hadzabe and the Datoga is one of mutual dependence. The Hadzabe trade wild honey, game meat, and animal skins to the Datoga; the Datoga supply the Hadzabe with the iron arrowheads that make their hunting possible. It is a barter economy of ancient elegance, operating entirely outside the modern monetary system, in the shadow of the Ngorongoro escarpment.

The lake sits in the Gregory Rift e the eastern branch of the Oost-Afrikan Rift Valley e on Tanzania's border with Kenia, roughly 200 kilometres north of Arusha as the crow flies. It is approximately 57 kilometres long and 22 kilometres wide, but at no point more than three metres deep e a vast, shallow basin that is essentially a concentrate of the Rift Valley's geological identity. Its water has a pH of between 9 and 10.5 e comparable to bleach e and surface temperatures in the shallows around the hot springs that feed the lake's margins can exceed 60 degrees Celsius. Animals that die in the water and wash onto the shore are mummified by the mineral-rich environment, coated in soda and trona as their tissues calcify. Photographer Nick Brandt's famous 2013 series of these petrified animals e bats, swallows, flamingos e standing upright on the shore as if frozen in motion, brought Lake Natron's extraordinary character to global attention.

The colour of the water e which shifts from pale pink at the edges to a deep, visceral red at the centre during the dry season e comes from halophilic microorganisms, primarily cyanobacteria of the genus Spirulina. These microscopic organisms are the foundation of the lake's ecology: they are what the flamingos eat. The lake's extreme alkalinity and heat, which kill or repel virtually every predator, create the precise conditions that the lesser flamingo requires to breed in safety. Lake Natron is the only regular breeding site for the lesser flamingo in all of Oost-Afrika e accounting for more than 75% of the entire Oost-Afrikan lesser flamingo population. When between one and two and a half million birds are present on the lake, the aerial view from the escarpment rim shows a lake that is more pink than red e an almost impossibly vivid spectacle that is one of the most extraordinary natural sights in Afrika.

Opstijgend vanaf de zuidelijke oever van het meer, de volcano Ol Doinyo Lengai e 2,962 metres, its perfect conical summit frequently trailing a thin plume of smoke e is one of the most distinctive geological features in Tanzania. In the Maasai language, its name means simply "Mountain of God" e Ol Doinyo Lengai is the dwelling place of Engai, the Maasai creator deity, and its eruptions are interpreted as divine messages. The mountain is also geologically unique: it is the only place on Earth where natrocarbonatite lava is produced e a type of lava so rich in sodium and potassium carbonate that it flows at only 500e600eC (roughly half the temperature of conventional basaltic lava), appearing nearly black when it erupts and cooling rapidly to a pale, brittle white crust. The mountain's most recent significant eruption was in 2019. Scientists from around the world travel to Lengai precisely because nowhere else on Earth produces this phenomenon.