In 1879, an eight-year-old girl spotted painted bison in a Spanish cave, challenging scientific views of Ice Age humans

In the summer of 1879, an eight-year-old girl entered a cave in northern Spain and looked up.That simple act helped change archaeology.While amateur archaeologist Marcelino Sanz de Sautuola was looking around a cave in Cantabria called Altamira, his daughter María was ambling around the chamber, only for her eye to fall upon something her father had missed.

Above her head, adorning the low roof of the cave, were spectacular images of bison painted in red and black. The animals seemed to almost flow across the rock, their shape determined by the rock beneath.What María had seen was not just the discovery of a hidden gallery of images. It questioned the deepest assumptions about Stone Age people and demonstrated that those who lived at the end of the last ice age were sophisticated artists.The moment that everything changedAltamira Cave was first discovered in 1868 by local hunter Modesto Cubillas, but its true significance remained unrecognised until 1879, when María Sanz de Sautuola spotted the painted bison on the cave ceiling.The discovery immediately captivated Sautuola and, using his understanding of the stone tools and animal bones he had uncovered in his excavations, he realised the importance of the paintings. Sautuola published his findings in 1880, concluding that the artwork was Palaeolithic in date.

The reception to his announcement in the scientific community was immediate and dismissive.Many believed that humans who had lived during the ice age would not have had the artistic ability to produce works of art in such detail. It seemed too sophisticated, too detailed, and too eye-catching to fit nineteenth-century ideas about humanity's ancient ancestors.According to contemporary accounts, many prehistorians considered the artwork to be a modern fraud rather than genuinely ancient art.Why were the paintings so convincingly modernA big part of this disbelief stemmed from the quality of the artworks themselves.Altamira is famous for its impressive polychrome bison adorning its main chamber. The artists who created them not only painted the animals but also skillfully employed natural bulges and curves in the ceiling to give them a three-dimensional appearance.Even by modern standards, the effect is stunning.Reports state that the artists combined engravings with painting and deliberately used natural contours to create a sense of depth and form.

Horses, deer, hands and other figures are painted and engraved throughout the chamber. The artworks do not resemble the scrawls of a species struggling for survival, but show imagination, skill, planning and purpose.

A question of the human mindHowever, the paintings at Altamira did not merely provoke argument regarding their age.They prompted debate about human intellect. If the paintings were real, then humans in the last ice age would possess imagination, symbolic ability and artistic prowess far exceeding that which 19th-century scholars were previously prepared to concede.

Altamira led scholars to reconsider what early humans were capable of.Over the next decade or so, other discoveries of prehistoric cave art were made throughout France and Spain, each strengthening Sautuola's claim and making it impossible to dismiss Altamira as a fraud; the paintings finally gained legitimacy in the twentieth century.The cave later became one of the most important archaeological sites in the world and a testament to humanity's long artistic heritage.A gallery built over millenniaToday, scientific studies have discovered that Altamira's story is even more significant than it first appeared.A recent investigation using uranium-series dating by scientists from the University of Barcelona and other institutions determined that the decorated surfaces were produced over an extremely lengthy period. According to the University of Barcelonay, the cave's decorated surfaces were created over at least 20,000 years, between roughly 35,000 and 15,200 years ago.

The research also suggested that some of the earliest phases of the artwork were produced by the first Homo sapiens groups to settle in Europe.Altamira was not a single snapshot, but an ever-developing masterpiece which was visited and added to over millennia.From disbelief to protectionThe argument is no longer one of genuine versus false.Instead, scientists focus their energy and resources on the conservation of the site. A study published in the journal Sensors, available through PubMed, last year examined the structural condition of the polychrome hall at Altamira.

Ongoing research is required to monitor the geology of the cave as the paintings must be protected for their significance to our shared heritage.This is a huge shift. What was once believed to be impossible to comprehend is now subject to highly advanced conservation science.Why Altamira still mattersOver a century after María Sanz de Sautuola looked up to see her father's overlooked find, it remains one of archaeology's most significant sites. Its importance lies not only in the beauty of the artwork but also in what that artwork reveals. The cave helped overturn the belief that prehistoric people lacked creativity or cultural sophistication. It showed that humans living tens of thousands of years ago were capable of producing complex and powerful visual art.A little girl's observation helped prompt a fundamental reconsideration of prehistoric life.Altamira did more than add cave paintings to the archaeological record; it showed that art is one of humanity's oldest skills.