Ol Doinyo Lengai, the “Mountain of God” in the Maasai language, is an active volcano rising to about 2,960 m above the Great Rift Valley, just south of Lake Natron in northern Tanzania. It is the only active volcano known to erupt natrocarbonatite lava, which appears black when it flows and turns white as it cools.
The climb is steep and demanding, usually starting around midnight so trekkers reach the crater rim at sunrise, with views over Lake Natron, the Rift Valley escarpment and, on clear days, Kilimanjaro. The descent is made in the morning before the heat of the day.
Ol Doinyo Lengai is reached by road from Arusha via Mto wa Mbu, and is usually combined with a stay at Lake Natron to see its flamingos and the nearby Ngare Sero waterfalls.
