Walk – and crawl – through El Castillo cave to see the 40,000-year-old painting that has scientists questioning the origins of human creativity.

I gasped at my first glimpse of a cave painting: a crude red outline of a deer with one wild circle for an eye. Its iron pigments blazed under the lamplight. The illusion of a breastbone emerged, ingeniously, out of a hump in the limestone wall. After a while, a cave becomes a long black tunnel of sensory deprivation; the sight of this tender image jolted my breath back to life.

“Can you tell you’re in a sacred place?” asked Marcos Garcia Diez, the archaeologist who had agreed to show me some of the most breathtaking rock art ever created. “This cave is like a church and that’s why ancient people returned, returned, returned here for thousands of years.”

Jutting from the base of a mountain about 85km west of Bilbao, El Castillo is one of the world’s most celebrated rock art temples. When Homo sapiens first began their northward migration from Africa to Europe around 40,000 years ago, some joined the Neanderthals here in Cantabria, a region that is home to at least 40 painted caves, including El Castillo. So magnificent are the province’s primordial masterpieces that when Picasso visited, he reportedly declared, “We have learned nothing in 12,000 years.”

The entrance to El Castillo cave. (S.RECD/Government of Cantabria)

The entrance to El Castillo cave. (S.RECD/Government of Cantabria)

Unlike France, which has barred the public from entering its greatest cave art sites, Lascaux and Chauvet, Spain’s culture ministry has kept El Castillo open to the public, allowing up to 260 visitors per day. Officials even recently opened the nearby Altamira cave, the so-called “Sistine Chapel of rock art”, to five visitors per week through February 2015.

Incredibly, El Castillo’s deer painting, along with renderings of archetypal bison, horned ibex and extinct cows, were merely a prelude to my ultimate goal: to see, deep within the cave, an extraordinary smudge of calcite-encrusted red paint – by all accounts, a treasure found nowhere else on the globe.

Two years ago, Diez and a team of archaeologists discovered that the smudge – a red disc painted in a corridor known as the “Panel of Hands” – was much older than previously realised. In a 2012 study published in the journal Science, they revealed that the painting was at least 40,800 years old – making it the earliest-known cave painting on Earth.

Gallery of the Discs in El Castillo. (S.RECD/Government of Cantabria)

Gallery of the Discs in El Castillo. (S.RECD/Government of Cantabria)

Diez and his colleagues argued that the painting was so old, in fact, that it might predate modern man’s arrival in this part of the world, and thus may actually be the work of a Neanderthal. With more research, Diez thinks they will soon discover even older paintings.

The revelations did not come without controversy, but it wasn’t the methodology that experts quarrelled with. Many agree that the standard practice of radiocarbon dating is limited at best; it applies only to charcoal works and loses reliability after about 35,000 years. To go back further, into the age of Neanderthals, Diez and his colleagues borrowed a technique from military science for dating the radioactive uranium that appears in calcite. They tested formations of the mineral that had grown atop paintings in 11 caves, assuming that whatever its age, the underlying paint had to be at least as old, and possibly much older. (The method proved so successful that other researchers used it to make another major discovery in October 2014: a 39,900-year-old handprint in Indonesia that is now considered the world’s second-oldest painting.)

What did cause contention was the suggestion that Neanderthals may have been responsible for the art – a divisive theory that threatens to disrupt decades of scholarship on the origins of human creativity. Scientists have long claimed that our thicker-skulled ancestors were not intelligent enough to make art. But today, a growing number of scholars argues that the characterization of Neanderthals as boneheaded beasts is an outdated, sapian-centric construction – even a kind of bigotry. As Gregory Curtis described in his book The Cave Painters, some view Neanderthals as “the very first victims of imperialism”.

None of this seemed of particular interest to Diez, however, as he led me deeper into the cave, guiding me through narrow verges and up muddy inclines. He thinks of himself as a “dirt archaeologist” – more interested in exploration than debate.

Yet Diez still enjoys asking impossible questions about the meaning of cave art. “Why do you think they painted so many of these?” he said, squatting beneath a rough but unmistakable sketch of a bison. Before I could answer, he explained how some ethnographers theorize that ancient hunters painted these prized sources of meat with the shamanistic belief that pictures could summon the animals. This “hunting magic” theory works a little like voodoo: representation as actualisation.

Detail of two hands. (S.RECD/Government of Cantabria)

Detail of two hands. (S.RECD/Government of Cantabria)

While Diez forged ahead, I stopped at the Panel of Hands, the site of dozens of handprints stencilled in ochre. I held my palm up a few inches from one of the outlines. I wanted to press down upon it, as if to gain access to some ancestor who, 1,600 generations ago, also laid a hand against this stone.

When Diez turned back, he flashed his light on my hand, still mid-air. “That. What you’re doing right now,” he said. “That, I think, is the reason for the paintings.” As I looked at my palm still hovering over the handprint, I realised he was right.

It was the innate human impulse to connect to something bigger than oneself. The wall was more than a canvas, it was a threshold – “a being", Diez said. In this view, the cave is a kind of Palaeolithic church, where paintings are scriptures and creativity is the measure of divinity.

“We’re close,” Diez said as we continued down the rocky chute. By now, it had taken us nearly three hours to walk – and often crawl – through the 1km-long labyrinth, and I sensed that we were circling back near the entrance.

Sure enough, a minute later, the hollow widened and Diez flashed his light onto a low, shadowy wall. There it was: the oldest-known painting in the world. Nothing more than a fist-sized red splotch.

“Is it everything you expected?” he asked.

I fumbled for an answer, but only more questions came to mind: Was this the work of history’s first artist? Did it represent the moment mankind transcended the animals?

The marking struck me as a kind of vanishing point: the furthest visible moment on the plane of human history. Yet as I stood before it, all of time seemed to melt into illusion, and I began to understand why we so often describe the ineffable with inadequacies like "spiritual" or "transcendent". Sometimes we must simply surrender to the unfamiliar, to the limitations of our knowledge, perception and language.

So I replied, truthfully, "It's so much more.”

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