The place
Ruaha, in short.
Ruaha is what people mean when they say the southern circuit. It is bigger than the Serengeti, receives a fraction of the visitors, and holds a lion population of continental importance — prides here are unusually large, and the hunting is on a scale that surprises people who thought they had already seen Africa.
The Great Ruaha River runs through the eastern side and, in the dry months, is the only water for an enormous distance. Elephant, buffalo and everything else come down to it. The riverbed itself becomes a road, a waterhole and a stage at once.
It is a transition zone, which is why the species list is odd and rich: both greater and lesser kudu, sable and roan, and a mixture of eastern and southern African species you do not get together anywhere else.