The Chaimu Crater – meaning Devil Crater in the local Kamba language – is a volcano that was active just two centuries ago and is distinctive for its black colour, a feature of the solidified lava. The climb to the top of the hill and back takes around three or four hours and is a strangely surreal experience – the ground is almost entirely devoid of vegetation – but the vistas from the summit are breathtaking, overlooking the rugged expanse of Tsavo West National Park.