-These fragments come from the Monte Alegre region, in the heart of the Amazon, where this art form was born. ♪♪ Reaching the area requires a 400-mile journey upriver from the mouth of the Amazon, and then a connection with one of the river buses that travel to isolated villages. Archaeologist Edithe Pereira has been making the trip regularly for more than 10 years. And each time, it's a journey back to Amazonian prehistory. ♪♪ The very first traces of human settlement can be found here. Drawings on the rock face that date back to 12,000 BCE. ♪♪ But these decorations, that have lasted millennia, are now in danger. -[ Speaking native language ] [ Speaking native language ] -The biggest problem here today is wasps. [ Wasps buzzing ] A type of wasp makes its nest very close to the paintings. -[ Speaking native language ] -And sometimes on top of the paintings. -It's a very real risk for the paintings... and for the scientists. Several stings from these large insects can be fatal. [ Buzzing continues ] No loud talking or sudden movements. ♪♪ These are the only paintings in the area that have been successfully dated, and they are much older than was previously thought.