The JHB Red Bus Tour!

Cost: A one-day open bus tour costs R200 per adult or R180 if you buy online. Pay R100 (online) for children, while children under 5 travel for free (max 2 per adult).

The most cheerful way to discover Joburg is on the roof of a shiny red city sightseeing bus.  Hop on, hop off the red bus and choose how you spend your time. The City Sightseeing tour comes with audio commentary available in 15 languages. This tour is a great way to get the best views and vibes of the City of Gold. You should definitely add it to your list of fun things to do in Johannesburg itinerary.

Source: http://www.travelstart.co.za