The journey begins
The last time I visited Sterkfontein Caves was on a school tour in Standard 5. I remember scrambling down into a gloomy cavern, where someone from Wits University told us all about archaeology and how we were related to funny looking bowlegged creatures called australopithecines.

Creepy caves
A lot has changed at Sterkfontein since then. A modern building now squats on the landscape, with a museum, gift shop, restaurant and ticket office. A guided tour of the caves is included in the ticket price, so while I wait for the next tour to start, I take a stroll through the museum. It’s cleverly done. The displays are engaging and the illustrations of what ancient hominids may have looked like are so lifelike they’re almost creepy.

Mrs Ples
Sterkfontein’s major claim to fame is Mrs Ples – an almost complete fossilised skull of Sterkfontein caves an Australopithecus africanus believed to be more than 2 million years old. Mrs Ples was discovered in 1947 by palaeoanthropologist Dr Robert Broom and the discovery sent ripples through the scientific world, because it added weight to the theory that our human ancestors originated here in South Africa. But now these caves are also the site of a much bigger, ongoing discovery.

A grand discovery
In 1997, while sifting through some fossils in a storeroom at Wits University, two fossilised feet caught the attention of another palaeoanthropologist, Dr Ron Clarke. Italian limestone miners did substantial blasting in the caves during the 1920s and the feet looked as if they’d been sheered off by a blast, rather than chewed off by a predator. Clarke figured that if the feet had survived then there might be more. He enlisted the help of two experienced fossil hunters, Steven Motsumi and Nkwane Molefe, who went back to the caves to look for the rest of the skeleton. Within two days, they found the lower legs, still encased in rock in one of the cave chambers, and attached to them were pelvic bones, a spinal column, a rib cage, arms and a skull. It was a staggering discovery – the first virtually intact Australopithecus skeleton ever found. Clarke christened it Little Foot. Little Foot is at least 4 million years old, very close to the fork in the road where modern humans diverged from ancient apes. But excavating the fossilised bones has proved to be laborious, painstaking work: 12 years since those delicate feet were discovered, Clarke and his team are still working on getting the skeleton out of the crumbly rock. In the mean time, the scientific world holds its breath. “Every year they say they’ll have the skeleton out,” tour guide Arend Mothokgo chuckles. “And every year they ask for another year.” We’re deep in the belly of the caves now and the sounds of Little Foot’s excavation echo from a separate tunnel, behind a locked steel gate.

Join the group
Our tour group consists mostly of foreign tourists – an American woman, two Dutch backpackers, a German couple and some Australians – and we’re wedged between two big school groups. The kids giggle and call out, waiting for their voices to echo back, just like I did in Standard 5. Further on, Arend lets us touch part of a fossilised spinal column from a prehistoric animal sticking out of the cave wall. It feels cool, an extension of the rock itself. The unfortunate creature would have met its end in the same way that Mrs Ples and Little Foot did: by accidentally falling through an open shaft and spending the next couple of million years slowly solidifying, as ice ages came and went and civilisations rose and fell.

A genie joke
At the end of the tour, outside the cave, we congregate around a bronze bust of Dr Broom. We have a choice: to rub either his nose for luck or his hand for wisdom. I waver: luck or wisdom? It sounds like one of those genie jokes. The Australians start muttering impatiently behind me, so I impulsively reach out and rub Dr Broom’s hand, where it cradles Mrs Ples’s skull. Wisdom it is then; they say you make your own luck.