I have added photos from the Constitution Hill in Johannesburg, South Africa. It is an amazing place, highly recommended to visit.
Under the apartheid government, only whites were held in the Old Fort itself, except for Nelson Mandela, who was given a bed in the hospital section when he was as an awaiting-trial prisoner in 1962 prior to the Rivonia Trial. Joe Slovo, Bram Fischer, Albert Luthuli and Robert Sobukwe were also inmates.
The site housed prisoners until 1983, when it was closed.