In 1879, a landowner and amateur archaeologist named Marcelino Sanz de Sautuola ventured into a newly discovered cave system in northern Spain. Hoping to find prehistoric tools, he kept his eyes fixed on the ground as he waded through the cave’s winding, low-roofed tunnels. Were it not for his eight-year-old daughter, Maria, who was looking at the cave’s ceiling as opposed to its floor, he might well have missed out on the single biggest discovery of his life.

“Look papa, bulls!” she cried out, pointing to the dozens upon dozens of cave paintings that filled up the rock wall above their heads.

Located a little over an hour’s drive west of the city of Bilbao, the Altamira (“high view”) Cave is home to some of the most famous prehistoric paintings in the world. They are not only noted for their age—more than 20,000 years, according to some estimates—but also for their quantity (around 930). Equally impressive are their excellent state of preservation, courtesy of the cave’s stable climate, and visual complexity: aside from bulls, the cave walls are populated by paintings of deer, oxen, boars, and humanoids, many of them rendered using pigment of different colors.

a black and white photograph of an old white man with a large beard and mustache wearing a black and white suit

Don Marcelino Sanz de Sautuola (1831-1888). Photo: Fine Art Images/Heritage Images/Getty Images.

Today, all of these qualities make the Altamira Cave a treasured world heritage site and popular tourist destination, attracting as many as a quarter of a million visitors each year. Back in the late 19th century, however, the cave had a rather different reputation.

Although it is difficult to imagine, the scientific community of the time reacted to Marcelino’s discovery with a combination of chuckles and raised eyebrows. Because no one had ever seen cave paintings before, no one considered primitive humans capable of creating it. Primitive humans, the prevailing line of thought prescribed, were just that: primitive. They were beastly, barbaric, incapable of communicating through symbols and creating anything that could be called “art,” scientists thought.

The Altamira Cave controversy

Convinced of the paintings’ authenticity, Marcelino tried in vain to persuade his contemporaries. In an 1880 pamphlet titled “Brief notes on some prehistoric objects in the Province of Santander,” he estimated that the artwork preserved inside the Altamira Cave had been created sometime during the Paleolithic period.

The pamphlet, though well-argued and ultimately correct, was met with skepticism. One influential voice of the time, the French archaeologist Émile de Cartailhac, went as far as to denounce the paintings at Altamira as forgeries. This opinion, which seriously tarnished Marcelino’s professional reputation, prevailed until his death in 1888.

It wasn’t until other collections of cave paintings were discovered in France that de Cartailhac changed his mind. In a 1902 article titled “Mea Culpa d’un sceptique,” or “A skeptic’s apology,” the archaeologist admitted that he had been wrong. In doing so, he not only rehabilitated Marcelino’s life and legacy, but also urged the scientific community to stop considering prehistoric humans as primitive and culture-less, opening the door to archaeological and paleontological paradigms that survive to this day.

Nowadays, prehistoric humans are no longer regarded as uncivilized—far from it. Excavations and research have shown that people from the Upper Paleolithic period engaged in all kinds of cultural production. Aside from painting cave walls, they crafted tools, jewelry, and clothing, and maintained complex social networks. None of these discoveries would have been possible if, like Marcelino when he first stepped inside Altamira Cave, the scientific community had kept on looking down.