There are two types of rhinos found in the South Africa.  The black rhino is the smaller of the two, and distinguishable by it's hooked upper lip.  It is extremely rare and we've only seen it from a distance.

We found the rhino below in Hluhluwe-Umfolozi Game Reserve.  An adolescent, this small male only weighed about 1,700 - 1,800 lbs.

The white rhino (below) is far more common between the two.  It got it's name from the Afrikaner word for wide--a reference to it's square upper lip.  Since it happens to be a lighter shade of gray than it's black cousin (left), so the name stuck.

The two white large rhino above may be the same animals, but we're not sure.  We found them in a very remote part Hluhluwe-Umfolozi (there weren't even paved roads on this part, and we didn't see another car for at least an hour).  They were huge.  Full grown adults weigh nearly 3,000 lbs. and these had to be right up there (each was as big as a mini van).

The rhino on the right had just crossed the road about 10 or 15 yards in front of us with it's mate.  We tried to drive past them, and just the sound of the engine revving caused the one in the photo to spin around and face us.  You haven't seen anything until you've seen a 3,000 lb animal move with lightning speed and stare you down.  We put the car in neutral,
and slowly coasted backward until the rhino turned back to its grazing. 
Needless to say, we gave it plenty of space before driving on!