Ol Doinyo Lengai Trekking

Experience the Majesty of Ol Doinyo Lengai Trekking

Explore the extraordinary adventure, vibrant culture, and stunning landscapes awaiting you at Mount Ol Doinyo and Lake Natron.

Ol Doinyo Lengai volcano, altitude 2,960 meters (9,711 feet), is a unique and extremely fascinating volcano that towers above the East African Rift Valley in northern Tanzania, just south of Lake Natron. It is the only volcano in the world that sometimes erupts natrocarbonatite lava, a highly fluid lava that contains almost no silicon.

Natrocarbonatite lava is significantly cooler than other types of lava, with temperatures around 950 degrees F (510 degrees C), compared to basaltic lavas, which exceed 2000 degrees F (~1100 degrees C). It is the most fluid lava on Earth. Due to its low gas content, natrocarbonatite lava can flow smoothly like a whitewater stream, exhibiting a viscosity close to that of water.

Natrocarbonatite lava glows orange at night, but is not nearly as bright as silicon-based lavas since it is not as hot. During the day it is not incandescent; most flows look like very fluid black oil, or brown foam, depending on the gas content. In the past, some visitors to the crater believed they were seeing mud flows. Most newly solidified lava is black and contains crystals that sparkle brightly in the sun.

There are also occasionally small flows referred to as “squeeze-ups,” which appear light gray in color both when they are actively flowing and after they have solidified and hardened. When this natrocarbonatite lava comes into contact with moisture, it quickly changes to a white color due to chemical reactions that take place as the lava absorbs water from the environment.