Lovers of military history are sure to enjoy a tour of the Ditsong National Museum of Military History. The museum, located on an 80ha site next to the Johannesburg Zoo, houses weapons and other artefacts from the many conflicts that South Africa has been involved in through the centuries including the Anglo-Boer Wars, the Anglo-Zulu War, World War I and II, the conflict in South West Africa (present-day Namibia) as well as items relating to the armed struggle against apartheid.
The museum was opened in 1947 by South Africa’s then Prime Minister General Jan Smuts, following the end of World War II. The museum contains a fascinating display of old weaponry, including some of the first heavy artillery guns which were used in the Anglo-Boer Wars such as the Maxim machine gun, the howitzer, automatic handguns and magazine-fed rifles.
Artefacts dating from the first and second World Wars include armoured fighting vehicles, uniforms and medals. A popular feature of the museum is the many aircraft on display, including aircraft from the world wars, some of which are the only ones of their kind left in the world. Among the 40,000 items in the collection there is also a wealth of more modern exhibits relating to the apartheid-era conflicts in Angola, Namibia and within South Africa which give important insight into the country’s recent history and explores another facet of Johannesburg tourism. 
 
If you're looking for things to do in Gauteng, then there's no shortage of options. Guided tours are available on request during the week, and the library and photographic archives are available for research purposes. In the museum’s library, visitors can view original documents from the struggle against apartheid, as well as personal military journals and history books.
References

 <p>https://www.gauteng.net/index.php/attractions/south_african_national_museum_of_military_history/   <p>

Further Reading
https://www.sahistory.org.za/article/world-war-i
https://www.sahistory.org.za/.../second-world-war-and-its-impact-1939-1948
https://www.sahistory.org.za/.../afrikaners-and-second-world-war-rodney- warwick
https://www.sahistory.org.za/.../world-war-i-and-south-african-native-labour- contingent
https://www.sahistory.org.za/.../cape-coloured-corps-and-first-world-war