The base of Ol Doinyo L'Engai, on the Engaruka Plains, lies at about 800m. The Masai's 'Mountain of the Gods' is the only active carbonate volcano in the world. The steep ascent to the top (currently just under 3000m) requires determination and good fitness levels, but the views alone are more than worth the effort. It is usually possible to stroll over solidified lava flows, and walk amongst the lava cones belching out sulphuric gases. Ideally the hike begins at 1-3am, and the summit reached as the sun rises - you cannot have too much film for your camera!