Ol Doinyo Lengai Volcano has the coolest lava of any volcano. It erupts at less than 600°C and most eruptions at the volcano are small. This temperature is so low that the molten lava appears black in sunlight, rather than having the red glow common to most lava. It is also much more fluid than silicate lavas. The rocks formed by Ol Doinyo Lengai are vulnerable to rapid weathering, quickly turning from black to grey in color. The resulting volcanic landscape is different from any other in the world.

The climb up Lengai is very difficult. You start off the six-hour climb at around mid-night in order to get to the crater rim by sunrise. After resting, you may explore the crater where you can see smoke escaping from the cracks in the earth.
 
The landscape around Lake Natron with the steep rising Ol Doinyo Lengai is breathtaking, a must for photographers.