Matobo National Park in Zimbabwe, where a group and I tracked wild Rhinos on foot, thats right, on foot.
We got close, disturbingly close. That photo below was taken with a lens set at 176mm and is not cropped. 176mm aint terribly long, I'm not sure how far away we were but it was close enough that if the Rhino had decided it didn't like one of us were were doomed.
Seriously though, White Rhinos are relatively timid and can be approached quite safely providing you do what your guide tells you (basically shut up and move slowly). All in, this was a day I'm not likely to forget in a hurry.