Basran Burhan was born in Indonesia, on the centrally located island of Sulawesi. He studied archeology at Hasanuddin University, at first, he told me, mostly because he liked how it involved “a lot of outdoor activities.” After graduating, in 2010, he worked for a few different Indonesian research and cultural heritage institutions. He also became an independent archeologist, helping organize excavations for a researcher named Adam Brumm at Griffith University, in Australia. Burhan’s field work struck Brumm as exceptional, and on the strength of it Brumm tried to get Burhan into a Ph.D. program. But Burhan’s imperfect English delayed this project for a number of years. Instead, he kept working for Brumm and his team.

In 2017, Burhan was helping Brumm and other researchers plan their next season of fieldwork: searching for evidence of Paleolithic humans in Sulawesi. Earlier that year, Brumm had briefly explored a new area on the island that seemed promising. Burhan and a team of six Indonesian archeologists were sent there on a field exploration.

The survey lasted for several weeks. At some point, poring over a map of the island’s southern region, Burhan found his eyes drawn to an area he’d never noticed, let alone visited—a valley in a mountain region twenty miles or so northeast of the city of Makassar. There were no roads into the valley, and there was nothing on the map to suggest a way through the bush and mountain peaks. The map did indicate rice paddies and other signs of human habitation, but Burhan didn’t know if the area was currently populated. A good part of archeology is simply exploration. Burhan thought, Why not?

Burhan and his team asked for directions from whomever they encountered, and continually got lost. But eventually they found a path through a cave that led into the hidden valley. The area was inhabited by an especially isolated group of Bugis people, an ethnic group of southern Sulawesi who recognizes five separate genders. The Bugis claimed never to have seen a single Westerner in their valley.

Burhan and his team began to explore the caves in the area and, a few days later, he entered one of them alone. Burhan glanced up and saw a painting of a familiar animal: a Sulawesi warty pig, a medium-sized, hairy boar with small pointy ears and short legs. Burhan had grown up with just this sort of wild pig, which is relatively common on Sulawesi, and which Burhan described to me, laughing, as a crop-destroying nuisance, akin to “a plant disease.” Gazing with recognition at this pig, Burhan also noticed the painted silhouettes of two human hands toward its rear. The over-all look of the art work suggested to Burhan that it was very old—but how old?

Thus began a long process of trying to give the cave art a proper date. Experts were brought in from Griffith. Maxime Aubert, an archeologist and geochemist, decided to use a method called uranium-series dating. He removed some of the calcite on the surface of the painting, which archeologists sometimes call “cave popcorn,” and then analyzed it. Anything under the calcite layer had to be at least as old as what was on the surface. A number of problems arose with the machine that actually did the dating—the Nu Plasma Multi Collector Inductively Coupled Plasma Mass Spectrometer. Like “a Formula One race car,” Aubert said, it requires a team of highly trained engineers just to keep it going. Still, months later, a date was handed down: the painting of the warty pig was at least 45,500 years old. This makes it the oldest known example of figurative cave art in the world.