I found this beautiful little fenced-in park very close to the popular Rafikis restaurant, at the base of Kloof Nek Road (map). Judging by the look of the old tyre, this seesaw must surely have been here for many years.
If you're ever in the area, stop for a moment to check it out - it has the most beautiful, huge trees - and in some way reminds me of Paris. It's not quite the Tuileries or Jardin du Luxembourg, but still, it's a very pretty part of the city.