Discovering Ol Doinyo Lengai: Tanzania’s Unique Nitrocarbonate Volcano

Nestled in Northern Tanzania, just south of Lake Natron, Ol Doinyo Lengai rises to an altitude of 2,960 meters (9,711 feet), dominating the East African Rift Valley. Known as the “Mountain of God” in the Maasai language, this active stratovolcano is a geological marvel, attracting geologists, thrill-seekers, and nature enthusiasts alike. What sets Ol Doinyo Lengai apart from every other volcano in the world? It’s the only volcano that occasionally erupts natrocarbonatite lava—a highly fluid and unique type of lava with almost no silicon content. 

What Makes Ol Doinyo Lengai’s Lava So Special?

Unlike typical lava, natrocarbonatite lava is significantly cooler, flowing at around 950°F (510°C) instead of the usual basaltic lava temperatures of over 2,000°F (1,100°C). This rare type of lava is also extraordinarily fluid, resembling a stream of black oil with the consistency of water, giving Ol Doinyo Lengai its unique geological charm. At night, this lava glows a dim orange, unlike the vibrant glow of hotter, silicon-rich lava, and during the day, it often appears as a black, oily flow or even brown foam, depending on its gas content.

Another striking feature is how natrocarbonatite lava transforms when exposed to moisture. Fresh flows harden quickly, turning white upon contact with water due to rapid chemical reactions. This whitening process can take days or weeks in dry conditions but happens almost instantly during rains. Visitors to the crater often find light gray “squeeze-ups”—small lava flows that lighten upon solidifying, forming a surreal, otherworldly landscape.

Ol Doinyo Lengai’s Explosive Eruptions

Ol Doinyo Lengai has periods of explosive activity in addition to its unique lava flows. During these explosive eruptions, the lava’s silicate content increases, reducing its fluidity and resulting in ash eruptions and the ejection of volcanic bombs. Notable explosive eruptions occurred in 1966-67 and more recently in 2007-08, adding to the volcano’s volatile allure.

The Mystery of Ol Doinyo Lengai’s Lava

Despite years of observation, Ol Doinyo Lengai’s unique volcanic activity remains an enigma. Scientists are still unraveling the mysteries of its plumbing system, gas content, and the chemical evolution of its natrocarbonatite lava. This unpredictability adds to the allure, as no one truly understands why eruptions sometimes give way to explosive events or how these activities relate to regional seismic events, such as the earthquakes preceding the 2007 eruption.

3-Day Ol Doinyo Lengai Climb Itinerary

For adventure lovers, a climb to Ol Doinyo Lengai is a bucket-list experience, offering an exhilarating ascent and unforgettable views at the summit.

Day 1: Begin your adventure with a morning departure from Moshi or Arusha. Drive for about 5-6 hours to reach Ngaresero Village near Lake Natron. Dinner and an overnight stay at the camp site near Oldoinyo Lengai

Day 2: Start the climb early at 1:00 a.m., ascending Ol Doinyo Lengai under the stars. Reach the summit by sunrise, take in the breathtaking views, and then descend back to base. After the climb, enjoy a refreshing break and dinner at the camp site near Oldoinyo Lengai.

Day 3: After breakfast, return to Arusha or Moshi, bringing your Ol Doinyo Lengai adventure to a close.

Essential Gear for Climbing Ol Doinyo Lengai

Sun Protection: Hat, sunglasses, and sunscreen
Lightweight Layers: Rainshell, fleece, and long-sleeve shirts
Footwear: Hiking boots with ankle support, Teva sandals, or flip-flops for camp
Accessories: walking poles, gaiters, and head torch
Hydration: Three 1-liter water bottles (3 liters total capacity)

Planning Your Ol Doinyo Lengai Adventure

With its breathtaking views, fascinating geological phenomena, and thrilling climb, Ol Doinyo Lengai offers a unique experience for travelers looking to go beyond the typical safari. As Tanzania’s “Mountain of God,” this remarkable volcano promises an unforgettable adventure in one of Africa’s most stunning natural landscapes.