The area is access sensitive
The Rocklands permit works nowadays also at the Tea Garden. So you don't need a special permit anymore.
Drive 500m past Klein Kliphuis (The Tea Garden) on the way down to Clanwilliam and park on the left in a large pullout. Walk back up the road and cross the fence before you get to the old cement dam. Follow the path right towards the large overhanging cave that can be seen from the road.
And please remember to behave, don't shout, don't litter and the usual good manners. The Tea Garden is close, so behave!