(Image credit: Flickr user flowcomm)
Ponte City, also called Ponte Tower, is a 54-story cylinder of apartments in Johannesburg, South Africa. It was built in 1975 as luxury housing. The 32,000-square-foot core of the building is open space, with windows facing inward from each apartment as well as outward. During apartheid, white families lived in the outer apartments, with windows overlooking the city, while their black servants lived facing the inner core.
(Image credit: Flickr user SprachLos1)
The building, visible from all over the city, became an icon of the Johannesburg skyline. As the neighborhood declined, so did the building. Gangs moved in, and the site became a hub of drugs and prostitution in the 1990s. The building became dangerous, with three stories of garbage piled in the central core.
(Image credit: Kemptonreporter)
Investors evicted almost all the residents in 2007 to begin a massive renovation, but abandoned the project when the financial crisis hit. The original owners then took a second look and started their own redevelopment. After much work, Ponte Tower is once again a safe place for families and professionals to live, and more people apply for apartments every day.
Philip Bloom made a short documentary on the history and the rebirth of Ponte Tower.
-via reddit
Johannesburg building codes apparently require all kitchens & bathrooms to have windows, so the center was left empty for that reason. So there is a corridor around the inside/middle of the tower that leads to your front door with the "back" of the apartment would be the outside walls.
A post from December of 2012 on Story of Bing which shows a finished apartment & hallway.
I saw the same comment about black servants forced to live on the outer ring, but all of them seem to be phrased the exact same way, giving it the feeling of an urban myth. Reputable news sources (CSMonitor, Mail & Guardian, etc) never make that claim, despite the articles mentioning race and how the building was effected by the end of Apartheid and "white flight".
Christian Science Monitor: http://www.csmonitor.com/World/Africa/2008/0212/p20s01-woaf.html
Mail & Guardian: http://mg.co.za/article/2012-04-20-pontes-fourth-coming-an-urban-icon-reborn
Story Of Bing: http://www.storyofbing.com/2012/12/the-ponte-city-johannesbur/