Fully agree with the above. JNB airport is not the sort of place I'd want to spend a day! The Rand is so weak right now that it would be a shame not to take advantage. You could easily rent a car and, as someone mentioned above, visit the lion park. There's also the lion and rhino park just a little further on, which is an even better experience. In each of these places an encounter with lion cubs is about £1.50. It's so ridiculously cheap at the moment! If that's not your thing, take the Gautrain into Sandton and check out the Canary Wharf of Johannesburg. There are some lovely hotel spas, such as the Maslow or the Sandton Sun, offering very well priced treatments. A 90 minute massage, for example, will set you back about £30. You could then relax on the Sandeck and have some lunch in the sun. The South African Breweries World of Beer tour is Johannesburg's top tourist attraction and well worth a visit if you're interested in the brewing process or in finding out how a small local brewery, founded in 1895, became the world's second largest beer company. There is, of course, also the huge bonus of getting to taste lots of different beers You can get there in an Uber from Sandron for just a few £s. There's just so much to do and see that it would be almost criminal to waste the day in OR Tambo. Oh, and if you want to bring me a few bottles of Chocolate Block from the airport, that would be fine too