Advise needed please, riding from Cape Town to Robertson.

Som friends an I are going to ride from Cape Town to Kleinmond and then from Kleinmond to Robertson up into the mountains for Sarurday night.
The route we are going tp follow from Kleinmond is from Sormsvlei through McGregor up to Robertson, these are nice gravel roads etc.

The part I need some help with is from Cape Town to Kleinmond, looking for gravel roads. All I can find is from Grabouw via Highlands road but I don't know where it starts.

Does someone know where Highlands starts or maybe more gravel suggestions.

Thanks all.