A t Groot Constantia, the oldest wine farm in South Africa , the 450,000 visitors who pass through its gates annually can admire the picturesque vineyards sloping towards a bay ringed by mountains or enjoy a glass of sweet Grand Constance, reputed to have been Napoleon’s favourite wine.

Unusually among the region’s old vineyards, there is also a museum that includes the history of slavery, run by state body Iziko Museums. Panels display information about enslaved people – about 30 of whom lived on the estate at any given time from its founding in 1685 until slavery was abolished in 1834 by the British colonial government – detailing everything from their work to what they ate.

Two plaques list the names of people forcibly taken from Mozambique, Madagascar, India, Sri Lanka and Indonesia.…