The place
Tarangire, in short.
Tarangire is the park most first-time itineraries treat as a warm-up on the way to the Serengeti, and that is a mistake. In the dry season it holds elephant densities that the Serengeti cannot match, and it does it against a landscape of baobabs that looks like nowhere else on the circuit.
The whole thing turns on the Tarangire River. From June the surrounding country dries out and animals walk in from a vast area to drink — elephant in herds of a hundred, buffalo, zebra, and the predators that follow them. By November the rains scatter everything again.
It is also quiet. Two hours from Arusha, and yet most vehicles pass straight through on the way north. Stay a night rather than doing a day trip and you will often have the southern swamps to yourself.