In the autumn of 1879, Spanish nobleman and amateur archeologist Marcelino Sanz de Sautuloa and his young daughter, Maria, set out to explore a cave in the hillside of Altamira, not far from the family estate in northern Spain. As a gentleman scholar, De Sautuola took a serious interest in finding out more about the prehistoric past.

Like other archaeologists of the day, he assumed the ancient people who once sheltered in this area where little more than savages, hardly better than apes and certainly incapable of any kind of achievement. One day while De Sautuola was digging in the earthen floor of the cave, hoping to discover some prehistoric bones or tools, young Maria wondered off to explore on her own. It was not long before she cried out, "Papa. Look, oxen."

She didn't realize it at the time, but Maria had just become the first modern human to set eyes on the first gallery of prehistoric paintings ever to be discovered. "I was overcome with amazement," De Sautuola wrote, "What I saw made me so excited I could hardly speak." When De Sautuola came over to see what she was looking at, he saw a ceiling dominated with dozens of paintings...but they were not of "oxen"—they were aurochs, a species of ox that had long been extinct.