The Castle of Good Hope doesn't look like anyone's idea of a castle. No spires, no towers. Built from sturdy rock in the 1660s, it's a five-pointed star fortress, each bastion named after a title of the Prince of Orange. As the administrative nerve centre of the Dutch East India Company, the VOC, it governed the Cape for over a century.

Its location tells a story. The main entrance once faced the sea, until flooding made that untenable. Strand Street nearby takes its name from the Afrikaans word for beach. The sea is long gone, reclaimed in the 1930s, taking with it 70 shipwrecks now buried under tarmac.

Its dungeons held enslaved people accused of misdemeanours, and the fiscal who oversaw them was a feared man. VoiceMap's tours connect the Castle to the slave trade, the Kaapse Klopse carnival born on emancipation day, and Cape Town's long reckoning with its own history.