I would suggest leaving your car more or less at the given parking coordinates and going uphill from there. Go around the back of the koppie from the western side and approach it from behind. There are no clear pathways so you will have to make your way around and over the rocks, aim to get to the big rock fig tree on the north eastern side of the koppie.
Once you find the place, sit down, relax and enjoy the view of the dam and the surrounding pine tree plantations.
I'm not sure how accurate the GPS was up here so the hint is quite specific.