These mysterious underground structures were built 175,000 years ago by ancient humans

French researchers have discovered at the depths of a cave in southwestern France circular structures made of broken stalagmites were raised by ancient man at least 175,000 years ago, proving that ancient mankind was much more sophisticated than previously believed. Researchers believe that the enigmatic underground chambers were raised by the Neanderthals.
This discovery provides the first conclusive piece of evidence that proves ancient man explored the underworld. It is still unclear whether the underground structures were used as a refuge or had a symbolic meaning to Neanderthals.
“This is completely different to anything we have seen before. I find it very mysterious,” said Marie Soressi, an archaeologist at Leiden University, who was not involved in the research
The Neanderthals lived in Eurasia for hundreds of thousands of years to about 40,000 ago, when they mysteriously disappeared after the arrival of modern humans. Archaeology has allowed us to understand how these ancient humans lived hundreds of thousands of years ago, and while archaeological records explain many features on their way of life, their food, and sociological interaction, little was known about their building skills which were believed to be extremely primitive.
The team of researchers lead by Jacques Jaubert from the University of Bordeaux, discovered nearly 400 fragments of stalactites and stalagmites stacked in several structures, including two with a circular shape, about 300 meters from the entrance of the Bruniquel cave. One of the intricate structures is 2 m wide and the other over 6.7 meters. The largest is composed of a “wall” made of up to four superimposed layers of stalagmite fragments of about 30 cm in length, with smaller elements glued obliquely in the middle.

Surprisingly, many of the stalagmites have a reddish color, and seemed to be darkened or cracked, suggesting that they were heated by small fires made voluntarily by its occupants, and not naturally. Researchers also recovered a bone fragment of 6.7 cm with signs of having been heated, and evidence of a similar effect on the rock above and surrounding structures.
French researchers have no doubt that the builders of the intricate underground structures were the Neanderthals, the only human species which according to them, occupied the zone over 170,000 years ago.
Scientists indicate that the ‘rings’ were made with pieces of similar size, pointing out that the construction was carefully planned. In addition, internal organization and the size of the structures support that these intricate early building projects were built by people 175,000 years ago.
“It’s becoming really clear with the Neanderthals, that given their abilities and capacities, there is not so much of a jump between them and contemporaneous modern humans,” Soressi said. “But this is very strange behaviour. I’d like to understand why they did it.”
For scientists, this discovery is yet another example that Neanderthals exhibited a complex social behavior hundreds of thousands of years ago. However, what they used the structures for is still not clear. Similar findings are needed in order to understand whether these are isolated constructions or were part of a complex used in regular planned activities, like a shelter or a place with symbolic meaning.
The structures remained extremely well preserved because they were sealed by calcite very shortly after being erected. This shows that early human ancestors had mastered the underground environment, a modern behavior that seems to have emerged earlier than thought.
The study was presented in the Journal Nature.