Tsavo West covers 9,065 square kilometres of volcanic hills, lava flows and acacia woodland, and is markedly more scenic and more varied than its eastern neighbour.
Its centrepiece is Mzima Springs, where some 250 million litres of crystal-clear water surface daily after filtering for decades through the porous lava of the Chyulu Hills. An underwater viewing chamber lets you watch hippo and barbel from below the surface.
The Shetani lava flow, black and barely vegetated, spreads across several square kilometres and is recent enough to appear in Maasai oral history, its name meaning devil in Swahili.
Tsavo West is greener and hillier than Tsavo East, with better cover and correspondingly harder game viewing, but the landscape itself does much of the work. On clear days Kilimanjaro rises across the border to the south-west.