Deep in the heart of Argentina, in a cave cut out of the rock by the swelling of the Pinturas River, is one of the most incredible collections of prehistoric art in the world. It takes a difficult journey to get to it, along tracks of shattered stone. However, it gives a glimpse into the cultural lives of our long-dead ancestors.
Humans first daubed paint on the walls of caves more than 40,000 years ago. Indeed, the first examples of cave art could be older than 65,000 years. That means that, most likely, Neanderthals painted them 20 millennia before the first modern humans set foot in Europe. And mystery still surrounds the purpose of the art that ancient people created.
The caves where paintings have been found are often in places that are difficult to get to, and researchers have found no evidence that they were houses or refuges. That has left scientists with two possible theories about the reason that our ancestors decided to make their marks.