The Burgundy Caves were discovered by a sientince. They  found paintings on the walls that told people where they were and how they could communicate with one another.  Sound would echoe from those spots and travel another spot in the cave system. Scientists discoverd that if you yell in the caves, the sound that you make bounces off the walls and comes back to you.  There is also something else that this sientince noticed " sound waves." When the sinentince noticed the sound waves bounces and can recored sound. The Burgundy Caves are located in France.