The caves are situated about 11km from Krugersdorp, on the Farm- 'Swartkrans'. They are believed to have been discovered in about 1896 or 1897, and were opened to visitors in about 1900. Previously, in 1895, geologist Dr D Draper had reported on the discovery of fossil bones in its vicinity. All though many years were to pass, before it was realised that Sterkfontein and neighbouring caves had been used by early human beings. Similar deposits were found thereafter on the neighbouring Farm of; 'Kromdraai', where a Palaeontological Reserve was declared in 1946.

Over the Years, this Area has become associated with the work of Dr Robert Broom, Professor Phillip Tobias and Dr Revel Mason, and since that time, excavations by other researchers, have made this one of the most important fields of scientific discovery in the World.

It was declared a National Monument under old NMC legislation on 23 November 1945. The surrounding Area has been declared a World Heritage Site and is referred to as 'The Cradle of Humankind'. A visitor's centre (Maropeng Visitors Centre) has been recently construction.

The Cradle of Humankind, is a Site of major significance to the Fossil Heritage of Humankind. This was a relatively small piece of Bushveld about 47,000 ha in size, the Cradle of Humankind earned its prestigious title, after a coincidence of seemingly unrelated factors exposed its treasure. It’s all about Dolomite, found in substantial quantities in the Sedimentary Rock, of the Cradle. Certainly, when it comes to the Cradle’s Caves and their ancient relics. (Amazingly without the presence of Dolomite, there would be no Cradle though.)

In the late 19th Century, Mining and Agriculture, established themselves as cornerstones of South Africa’s Economy. This led to a period of boom for the Witwatersrand: Settlers moved in, construction increased and Farms were established.
Mining activity, in what is now the Cradle, sprung up at Kromdraai (7 Km from Sterkfontein Caves), along the Blaauwbank River. 
Increased Mining, Agriculture and Construction Projects led to; an increased demand for the Lime found in Limestone. This was used in the Manufacture of Cement and also, as part of the Building Process. It was used in Agriculture to counteract Soil Acidity, and some Farmers, added Lime to Livestock Feed, to boost Calcium Levels. Miners used the material, to Neutralise the Acid used in Processing Gold. But accessing the Lime Caves, called for big-time Dynamiting, which exposed the Entrances to the Caves which, in turn, gave up their treasures to Science.
These were a series of dazzling fossil discoveries at the Sterkfontein Caves! The biggest of the Cradle’s Caves gave justification to the argument for Africa, as our Place of Origin. The most important fossil finds at this site are: “Mrs Ples” in 1947 and “Little Foot” in 1995. By the Wise Men; Professor Robert Broom (“Mrs Ples”), and Professor Phillip Tobias and Professor Ron Clarke (“Little Foot”). In 2008, Professor Lee Berger of the University of the Witwatersrand, brilliantly used the powerful tool- 'Google Earth'- to identify new Cave Sites, in the Cradle of Humankind. Berger noted, clusters of Alkaline(limestone) loving Trees such as the White Stinkwood and the Wild Olive. He was then able to identify 500 new, potential Cave Sites, at the Cradle.
At present there are more than 30 Fossil Bearing Sites, at the Cradle of Humankind. Where scientists have uncovered a large amount of some of the Oldest Fossils in the World. Sterkfontein Caves alone has produced in excess, of a third of the early Hominid Fossils ever found! 
Please be informed, Sterkfontein Caves is still closed until further notice, we're awaiting updates from the owners, and regret that we can't provide a reopening timeframe. Apologies for any inconvenience—your patience is truly appreciated.
On a brighter note, Maropeng Visitor Centre is open for tours every day, including weekends and public holidays.
The Maropeng tour includes:
- Museum guided tour
- Underground boat ride
- Vortex tunnel
Geolocation
-26° 38.7173", 27° 44' 0.3596"
References

https://www.maropeng.co.za/news/entry/caving_in_a_brief_history_of_the_cradle_of_humankind-  1 November 2011- JULIA LLOYD

https://www.maropeng.co.za/content/page/sterkfontein-caves

Further Reading

https://www.dailymaverick.co.za/article/2022-06-27-sa-back-in-contention-for-being-the-place-where-our-species-originated-following-new-sterkfontein-caves-discovery/

https://www.maropeng.co.za/news/entry/the_sediba_discovery 

https://www.sa-venues.com/things-to-do/gauteng/kromdraai-gold-mine/ https://www.eurekalert.org/news-releases/956985?fbclid=IwAR1ffjoR-OoV4aCr1wCjdCBQUvGcuOHi8C2ZzgYevEKdXK6TUD6mu6eW4ew#.Yrq_SNsHv0w.facebook

https://www.sa-airlines.co.za/blog/2020/02/11/visit-the-cradle-of-humankind/

https://www.yahoo.com/now/makes-archaeology-useful-well-exciting-140919160.html

https://www.theheritageportal.co.za/article/professor-revil-john-mason-1929-2020

https://www.google.com/earth/outreach/tools/

https://www.maropeng.co.za/content/page/sterkfontein-caves