I doubt that there is any place in South Africa that is as Scottish as the towns and regions already mentioned, but there are strong Scottish communities in various parts of South Africa.
Mostly they are in the cities, but in the Eastern Cape particularly there is a rural population that descends from the British settlers of 1820. Some of these families were Scottish, and the Pringle family has three farms between the towns of Bedford and Adelaide. The poet Thomas Pringle was the leader of the Pringle party of settlers.
The most Scottish part of South Africa would most likely be Gauteng. This is reflected in the tartan-wearing regiments raised there: the Transvaal Scottish (which had offshoots that were taken into other parts of the South African Army, including the artillery), the Witwatersrand Rifles (based on the East Rand) and the Pretoria Highlanders.
The Pretoria Highlanders were first raised on the eve of the Second World War as a project of the city’s Caledonian society.
While Natal did not produce a kilted regiment, it has a military pipe band attached to No 1 Medical Battalion.
In the old Cape Province there were First City in Grahamstown and Queenstown (Eastern Cape) and the Cape Town Highlanders in the Mother City.
Regards,
Mike