The Cradle of Humankind is one of eight World Heritage Sites in South Africa. Here, the landscape is dotted with subterranean limestone caves that have turned up a rich fossil record for human evolutionary studies, which lend credence to the 'Out of Africa' theory of where our ancestors came from.
About 50km north-west of Johannesburg is the Cradle of Humankind World Heritage Site, an area of undulating grassland, rocky outcrops and river courses typical of the Highveld before it was overtaken by urban sprawl.
It's a place that draws visitors from around the world for the fossil record that lies in the network of limestone caves beneath the surface.
Here you'll find the Sterkfontein Caves, Swartkrans and Kromdraai, among other fossil sites, all places that tell the story of what the world was like when our human ancestors were evolving some two to three million years ago.
At the Sterkfontein Caves alone, the remains of more than 500 hominids (the hominid family includes modern-day humans and their direct ancestors) have been uncovered, lending credence to the Out of Africa theory, which is that humans and their ancestors evolved in Africa first.
So rich is this hominid fossil record that the area was declared a World Heritage Site in 1999, one of eight in South Africa.
Fossils were first unearthed here in the 1890s when the caves were blasted open for lime needed for the extraction of gold discovered on the Witwatersrand in 1886. But it was only from the 1930s that serious scientific work started to take place.
One of the first major discoveries was that of 'Mrs Ples', a pre-human skull dating back more than 2-million years (Australopithecus africanus) unearthed by Professor Robert Broom and his assistant, John Robinson, in 1947 at the Sterkfontein Caves.
The skull was originally classified as Plesianthropus transvaalensis (hence the name) and was an adult version of the same species as the Taung Child, the tiny fossilised skull of a child about three years old that had been found at the Taung limeworks in what is now the North West province, and identified by Professor Raymond Dart in 1924.
Although smaller than us, Australopithecus africanus is regarded as one of our early ancestors because it walked upright. In 1997, a complete hominid skeleton called 'Little Foot', also found in the Sterkfontein Caves, was introduced to the world and is still in the process of being described.
In 2005, two more areas of significance were added to this World Heritage Site, bringing the number of official fossil sites in the Cradle of Humankind to 13. These were Makapan (in Limpopo) and Taung (in the North West province). Together all these areas are now known as the Fossil Hominid Sites of Sterkfontein, Swartkrans, Kromdraai and Environs, recognised by UNESCO for their significance in human evolutionary studies.
You'll find a small but good exhibition centre at the Sterkfontein Caves and a much larger, more interactive one at Maropeng.
And you can play, too
Aside from a visit to the Sterkfontein Caves and Maropeng, the official visitor centre of the Cradle of Humankind, 'the Cradle' as it is locally known is also a playground for the people of Gauteng, with a range of facilities and activities, including loads of accommodation choices, restaurants, coffee shops, conference centres, cycle tracks, horse trails and hot-air ballooning.