It was on Mogale City’s koppies, in its caves and valleys, that our ancestors took their first faltering steps towards controlling their world. It is the place we all began.

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FEW of the world’s great cities can trace their heritage back thousands of years, to early human settlements. Mogale City can trace its history back three million years.

Just 12 kilometres from the centre of Krugersdorp is a nondescript 47 000 hectare region of koppies, scattered shrubs and trees. Its tranquil rural appearance belies its importance, for this is a World Heritage Site, the Cradle of Humankind.

It is here that fossil evidence has been unearthed, tracing human activity back three million years. It is here that man’s earliest known mastery of fire has been found. It is here that humans probably took the first steps towards controlling their world, instead of being controlled by the forces of nature.

In all, some 40 percent of the world’s human ancestor fossils have been found here. There are 15 major fossil sites in the Cradle of Humankind, with Sterkfontein Caves the most well known.

More than 500 hominid fossils and over 9 000 stone tools have been found in the caves, and it was here that two finds that changed the way we view humanity and the history of human development were made: Mrs Ples (now believed to be a Mr Ples), an Australopithecus africanus dating back 2,5 million years was found by Robert Broom in 1947; and Little Foot, an almost complete ape-man skeleton 3,3 million years old was found by Ronald Clarke and Phillip Tobias in 1995. The bones were originally excavated in the late 1970s and had been stored in a box until the two scientists re-examined them.

The most recent find, announced in April 2010, is that of an entirely new hominid species, Australopithecus sediba. Scientists believe this fossil find will be the Rosetta stone of palaeoanthropology, the transitional species between Australopithecus and Homo.

Other sites in the valley include Bolt’s Farm, where the remains of three sabre-tooth cats have been found in a pit that trapped animals; Swartkrans, site of the earliest-known deliberate use of fire, around 1,3 million years ago; Haasgat, where the fossils of early forest-dwelling monkeys, around 1,3 million years old, were found; and Gondolin, where 90 000 fossil specimens have been found since 1979.

The area was declared a World Heritage Site in 1999. Although it is on privately owned land, any finds belong to the world, and the area is strictly controlled and protected.

Visitor centres

The Cradle of Humankind has two visitors’ centres: Maropeng and Sterkfontein Caves.

At Maropeng visitors can tour 2 500m² of exhibits, including taking an underground boat trip. Here they will view fossils, learn about how humankind came to be, and see one-million-year- old stone tools.

At Sterkfontein, visitors can tour the caves where the dramatic discoveries were made. Here, they can see a reconstruction of a mined cave, the cave formations, and the mammal and hominid fossils.

Beginnings

In the late 1890s, miners dynamited the Sterkfontein Caves, searching for limestone which they converted into quick lime, an element needed for the processing of gold and the manufacture of cement. They displaced the sediment and revealed entrances to the caves.

The rocks contain cylindrical shapes - evidence of early life called stromatolite, dating back 3,8 billion years. These organisms breathed in carbon dioxide and breathed out oxygen, thus increasing the earth’s oxygen levels and leading to the evolution of other forms of life.

Some 2,5 billion years ago, the area was a shallow inland sea. Over time, however, the water evaporated and the mud formed dolomite rock, in which the stromatolite are visible

Around two billion years ago a large meteorite, 10 kilometres in diameter, fell in Vredefort 100 kilometres south of Sterkfontein, leaving a massive crater now known as the Vredefort Dome. The entire area for hundreds of kilometres around was covered in debris, which helped preserve the gold reefs of the Witwatersrand, preventing them from being eroded - and also helped preserve the stromatolite rocks.

Some 3,5 million years ago, openings to the caves started appearing. They may have been occupied by sabre-toothed cats and other predators, which would explain why the remains of large herbivores like wildebeest, extinct zebra and buffalo have been found in the caves.

One of them is called Plover’s Lake Cave. It has been explored some 50 metres down, but beyond that point are a labyrinth of unexplored passages.

The nearby Wonder Cave has an enormous chamber with beautiful 15m high stalactite formations. The cave is believed to be 2,2 million years old, and bones of rodents, frogs, lizards and birds have been found in it.