There are loads of these caches in the Pretoria area, but not many in Johannesburg.
I've always been thinking of following in the footsteps of Cherokee SA. I found this secluded one with quite a nice view of a nearby school.
This is the cypress/pine looking tower, and an extremely tall one too. Not many newer towers are like this anymore. The cellphone companies have opted for the smaller "lamppost" versions which are cheaper and also don't need consent from residents.
There is parking right in front but please watch out for muggles. BE AWARE FOR YOUR OWN SAFETY!