Ol Doinyo Lengai: What’s it like to climb East Africa’s only active volcano?

As the sun sinks lower and the intense heat of the day begins to die down, we walk across the sticky mud flats towards the lake. In this remote landscape of northern Tanzania lies the mystical Lake Natron; behind us is Lake Natron Camp where I’m staying, and ahead, Ol Doinyo Lengai, East Africa’s only active volcano, towers in the distance.

Dust devils whirl over the fissured earth, and what little grass there is has turned to straw in the dry weather. The lake, however, is a shimmer of pink, as flamboyant flamingos move through the shallows, stirring up organic matter with their webbed feet and swinging their heads back and forth as they feed. When they tire of feeding, they strut in synchronized formations, like a fine-feathered flash mob—half-regal, half-ridiculous, blissfully unaware of how closely they resemble a marching band that got lost.

As my husband and I sit by the lake, we contemplate Ol Doinyo Lengai hovering on the horizon. When the sun sets this time tomorrow, we’ll be preparing for bed, ready to wake at midnight and head to the volcano for a moonlit hike to its 2,962-meter-high (9,717 feet) summit—a trek frequently billed as the toughest day hike in East Africa.

Fed by natural springs, Lake Natron takes its name from the rich mix of salts and minerals known as ‘natron’. In the dry season, the alkalinity is practically pure ammonia, and water temperatures can reach a scalding 60° Celsius (140° Fahrenheit). When water levels drop, the lake’s salts and minerals form a crimson crust over the surface, creating an incredible, inhospitable, alien landscape.

Just three meters deep, but 22 kilometers wide, Lake Natron is the breeding ground for two and a half million Lesser Flamingos. Evolved to withstand the lake’s high salt content and protected from predators by the lake’s toxic water, they make their nests on mounds of salty mud between August and October each year.

75 percent of the world’s Lesser Flamingos are born here, and it’s the lake’s algae, cyanobacteria, and salt-loving phytoplankton that flamingos feed on that gives their feathers its pink tinge.

Walking in almost total silence, we stop every hour or so for a breather. It’s slippery at times. At other times, some scrambling is required, and sometimes, we’re almost crawling on all fours.

While most visitors come for the lake, around 500 and 1,000 climb Lengai annually. Lengai is sacred to the Maasai who call it the ‘Mountain of God’. Our guide, Samuel Lesikar Liang’eri, or Samwely for short, grew up here in the shadow of Lengai. He tells us how he and his fellow Maasai believe the volcano to be home to their androgynous god, Enkai, the supreme creator and guardian.

“Enkai retreated here after being hit by a hunter’s arrow,” Samwely tells us, and still occasionally thunders their wrath “with eruptions and drought.” What also sets Lengai apart, is that this is the only active carbonatite volcano in the world. Carbonatite is a rare igneous rock, sometimes mixed up with marble, that’s 50 percent carbonate minerals.

It’s this rare natrocarbonatite lava that can erupt at temperatures of around 500-600° Celsius, making it the coldest erupting lava in the world. Lengai is an active volcano, with roughly 15 eruptions dated in the last century, the most recent being in 2013.*

Barely 24 hours after our flamingo encounter, I’m in the back of a Landcruiser, driving from the shores of Lake Natron to the base of Lengai. It’s dark and the car’s headlights reveal only the occasional twisted umbrella thorn or baobab tree in this otherwise bleak landscape.

It’s surprisingly warm for the middle of the night, and eerily quiet. I’d been expecting it to be cold, so had come with gloves, beanie and jacket. As I stuff them into my backpack, I start to wonder what else I’ve got wrong and just how prepared I really am. It’s too late for second thoughts.

Parking the vehicle, we alight, backpacks on and torches at the ready. It’s very steep—an almost-45-degree slope—but not so dark we don’t see a plump, pale scorpion scuttling across the path, illuminated in the wavering pools of light from our head torches. Shortly after, a snake slithers off the trail and into the undergrowth, retreating from our approaching footsteps.

Onwards and upwards, we push. Walking in almost total silence, we stop every hour or so for a breather. It’s slippery at times. At other times, some scrambling is required, and sometimes, we’re almost crawling on all fours. I’ve put my gloves on, not because it’s cold, but to protect my hands from the jagged rocks as I drag myself upwards on my hands and knees.

More than three hours into the climb, we pause in the dust for a break. Sitting quietly in the dark, somewhat overwhelmed by our surroundings, each of us silent, alone with our thoughts.

Pushing on, the top third of the climb has some near-vertical, rocky stretches, and as we approach the summit, gaps between the rocks emit plumes of sulfurous-scented steam. It’s still dark; the sun won’t rise for hours still.

In the half-light the scenery is otherworldly. Full of calcium, sodium and carbon dioxide, on eruption the natrocarbonatite lava has the look of a thick, black, viscous oil. But after cooling, it turns white, and combined with the white volcanic ash, gives the upper slopes a dusting of what looks deceptively like snow.

When the sun rises and casts a soft golden glow across the landscape, we’re almost halfway-down. It’s a relief to know the steepest part is behind us—and we’re able to hike the rest of the way in an upright position, on our own two feet.

Under the watchful eye of Samwely, it’s taken us nearly five-and-a-half hours to reach the top. Lengai has two summit craters: The southern one is inactive and filled with volcanic ash while the northern crater is the active one and 200 meters deep. The crater rim is wide and steep-sided, but walkable.

We shuffle our way through the loose scree and perch on the edge, staring down into the caldera. Unlike most volcanoes, the molten rocks in Lengai’s core is black. Looking down, the lava bubbles like boiling tar. Crimson phosphorescence breaks through cracks in the surface of the magma, glowing in the dark. A surreal whooshing, murmuring sound fills the air, like an angry, restless ocean. We sit silently, mesmerized.

With an hour to go before sunrise, we decide to begin the descent. We know the way down will be slippery and slow, and the plan is to complete the return hike before the heat of the day kicks in. It takes us around three hours to reach the base; sometimes crawling backwards, crab-like and ungainly, and sometimes simply sliding on our backsides… anything goes.

When the sun rises and casts a soft golden glow across the landscape, we’re almost halfway-down. It’s a relief to know the steepest part is behind us—and we’re able to hike the rest of the way in an upright position, on our own two feet.

As the sky lightens, the views stretch all the way to Mount Meru and Kilimanjaro in the east, Lake Natron and the Kenyan border to the north, and, in the west, across the undulating Sale Plains all the way to the prehistoric Gol Mountains with their spectacular rock formations, canyons and wide, meandering valleys.

As we reach the base, we see the Landcruiser waiting patiently, ready to return us to the comforts of our camp. The drive back seems quicker in the light, and we spend the rest of the day wallowing in a natural spring-fed plunge pool, while small shoals of endemic cyclids (freshwater fish) nibble at our tired toes, and Lengai looks benevolently down on us from a distance.

Climbing Ol Doinyo Lengai is not for the faint-hearted, that’s for sure. A certain level of fitness and a sense of balance will help, but it’s safe to say, it’s worth it, both for the unparalleled views and the sense of achievement.

I’m reminded of what Ake Lindstrom, professional mountain guide and founder of Lake Natron Camp had told me: “Lengai is one of the hardest one-day climbs in East Africa, but if you put your mind to it, put one foot in front of the other and take it slowly, when you get to the top, you’ll be rewarded with something that is quite unlike anything else in this world.”

He was right. Having faced the fire and fury of Lengai, I back down feeling like I’d climbed into the heart of Africa and touched the pulse of the earth, and it was worth every single step.

**

It takes approximately two hours to reach Lake Natron by (a bumpy and dusty) road from Manyara or Ngorongoro. Flights from Arusha Airport take around an hour.

The writer traveled to Lake Natron with specialist African operator Mahlatini Luxury Travel and stayed at Lake Natron Camp, a luxury eco-camp run by local Maasai, with profits going directly to their village. The writer’s climb was arranged by the camp.