The revered active volcano, Oldonyo Lengai, meaning "Mountain of God" in the language of the native Maasai people, is located 25km to the south of Lake Natron, in the heart of the Great Rift Valley.  

Rising more than 2,000 m above the Rift Valley floor, it is unique among active volcanoes in that the lava is erupted at relatively low temperatures (approximately 500-600 degrees Celsius). This temperature is so low that the molten lava appears black in sunlight, rather than having the red glow common to most lavas. The sodium and potassium carbonate minerals of the lavas are unstable at the Earth's surface, quickly turning from black to grey in colour. The resulting volcanic landscape is different from any other in the world.

A nearly perfect cone, about every seven years Lengai erupts and plumes of smoke billow out of the crater.  

A challenging hike to the top will sometimes offer an opportunity to view molten lava and is one of the highlights of an adventure safari. From the slopes of Lengai you have great views of the surrounding landscapes, particularly towards the dramatic steep western face of the escarpment that rises from the Great Rift Valley. For those able to summit, it is sometimes possible to walk across the crater floor, often to the edge of the molten lavas.

The ascent of Lengai is demanding on account of the day time heat (if climbing in daylight), lack of water, steep and unstable slopes of ash, crumbly rocks and considerable height gain, some 1600m. or just over 5,000ft. Starting from somewhere between 2300 and 0300 - depending on the perceived pace of the climbers - we quit camp beside Natron, climb through the darkness, and aim to emerge at the summit for one of the most spectacular sunrises many will ever experience.

Lake Natron can be reached by means of a tough six hour drive north west from Arusha by 4x4, via Mto Wa Mbu, through remote, dramatic and harsh terrain. More usually however, we approach from Mto wa Mbu, or overland via a walking safari that originates in the Ngorongoro Highlands.

The Ngaresero River provides an extraordinary and truly unexpected contrast to the heat and dust, as it flows clean and cool out of the rift valley wall into Lake Natron.

Covering 1,300 sq km and measuring 24 km wide and 56 km long, Lake Natron is the world's most important breeding site for the Lesser Flamingo that congregate there between August and October.

The sheer colour and scale of Lake Natron and its surrounding flanks, dominated by Oldonyo Lengai, is breathtaking. This bright red lake derives its colour from salt-loving micro-organisms that thrive in its alkaline waters.

The lake is the world’s most caustic body of water, and would-be predators avoid the saline water and leave young birds in peace. Those wanting to visit the shoreline should be aware that any footwear that comes into contact with the mud will likely be badly damaged, and should ask their guide to arrange to quickly clean off any mud that adheres.

Depending on rainfall, the lake’s alkalinity can approach that of straight ammonia, and when the lake is flooded with water that has heated underground, its temperature can reach a scalding 60 degrees Celsius (140 degrees Fahrenheit) as can be evidenced by the hot springs that sustain the lake.

While you may see game, such as giraffes, wildebeest, zebra, gazelle and even the odd lion and cheetah, close to Lake Natron, particularly in the wet season, this place is not so much about game viewing as experiencing the awe-inspiring space and immense views. This area is home to nomadic Maasai and it is really impressive to see how they manage to conduct a lifestyle, unchanged for many hundreds of years, in such a harsh environment.

For TK safari-goers, particularly those who has just endured a difficult ascent of Lengai, or trekked in from the Ngorongoro Highlands, one of the best attractions of the area is the opportunity to earn a well-deserved swim under the beautiful and dramatic waterfall that descends from the Ngaresero Springs.