There are plenty of things to do around Johannesburg.
Pilannesberg Game Reserve
Day trips to Pilannesberg Game Reserve and Sun City, but this is better as an overnight trip to get in the Night Game Drives which you have to go on a tour with. The animals are on the move in early morning and late afternoon/evening. This is the best time for viewing.
Definately do the one that does more of the Reserve.
Try to get an overnight trip because the animals are on the move more in the late evening(night Drive) or early morning (6am).
So if you get there in the afternoon you can do Sun City then organise a night drive.
The night drive has to be done by the park. Then get up early for the park opening +-06h00.
These are the times when you will see the most animals.
Below is a site you might be interested in.
Lessedi Cultural Village.
The is a recreation of variours tribal village styles. You do a tour of the various villages and the guide explains why the huts or kralls are built in that way, differing from another tribe. Then there is the traditional dancing follower by a sumptious buffet meal.
Union Buildings the government buildings.
Where the peace treaty between the boers and the brittish was signed. It was the headquarters of the British forces during the Anglo-Boer War (1899 to 1902).
The Voortrekker Monument.
Soweto and Appartheid Museum and Hecter Peterson Memorial.
This should be done on a halfday tour of Soweto
De Wildt Cheetah Research Project.
In the foothills of the Magaliesberg in South Africa's North West Province, the De Wildt Cheetah Research Centre is situated an hour from Pretoria. It offers you the opportunity to learn more about fascinating creatures such as the wild dog, cheetah and various species of owls and vultures.
Lion and Rhino Park
The reserve is situated in the "Cradle of Humankind", a declared World Heritage Site, about 40 km north-west of Johannesburg and 60km west of Pretoria. Here I was able to play with a lin cub for a reasonable fee. There is also a BBQ/Picnic area near the restaurant.