The farm dates back to 1682, a mere 30 years after Jan van Riebeeck of the Dutch East India Company landed to establish the first European settlement in the Cape [1], making it one of the oldest farms in South Africa.
If you have a spare moment, click though to the their website to read the Rustenberg story - surprisingly, it's somewhat interesting. :)
See this post for more about this photo and Rustenberg Wine's open gardens.