The oldest stone circles ever found date back to 175,000 years ago and were created by Neanderthals.The circular structures created from nearly 400 stalagmites in the Bruniquel cave show that Neanderthals were far more organised in their social structure than previously thought. The creation of these structures requires the mobilization of people who can lead, who can advise, who can manufacture, who can construct patterns, all while they needed a continuous source of light.