Johannesburg was a city in South Africa, in the Transvaal province. It had been visited at some point by the Doctor, and the Third Doctor said that he intended to someday return to it. (PROSE: Last of the Gaderene [+]Mark Gatiss, BBC Past Doctor Adventures (BBC Books, 2000).)
Tim Latimer's uncle had a six month posting in Johannesburg, claiming it to be "the most beautiful countryside on God's Earth." (TV: Human Nature [+]Paul Cornell, adapted from Human Nature (Paul Cornell), Doctor Who series 3 (BBC One, 2007).)
At some point in the history of the city, racial tensions between black and white humans had erupted into violence. (PROSE: Infinite Requiem [+]Daniel Blythe, Virgin New Adventures (Virgin Books, 1995).)
In 1999, records of a Beryllium chip were stored in a skyscraper in Johannesburg. Calum Bence was sent to recover them. (PROSE: The Danger Men [+]Error: Code 2 - no data stored in variables, cache or SMW.)
Torrance Hayton, as Trey found out, was from Johannesburg. (PROSE: Instruments of Darkness [+]Gary Russell, BBC Past Doctor Adventures (BBC Books, 2001).) Brockie was from Johannesburg, and thus spoke fluent Dutch. (PROSE: Players [+]Terrance Dicks, BBC Past Doctor Adventures (BBC Books, 1999).) Bliss was from Johannesburg. (PROSE: Last of the Gaderene [+]Mark Gatiss, BBC Past Doctor Adventures (BBC Books, 2000).)