May 27, 2016 10:26 AM EDT By Anita Valencia, UniversityHerald Reporter

Neanderthal is an extinct species but archaeologists are trying to track down the lives of cavemen in ice age.

Recent finding in France' southwestern Bruniquel Cave shows evidence of Neanderthals and their work. More than 400 sophisticated stalagmites inside the cave are believed to be a shocking ancient construction because according to scientists, Neanderthals were not intelligent to master such complex structure or even use fire as lighting. But the mineral formations found deep inside the dark cave, are not natural and these are the work of hands.

It becomes a huge and surprising finding because all of the recorded data proved no track of Neanderthals deep in the dark cave. The previous evidence only shows prehistoric Chauvet Cave paintings from 35,000 years ago.

The Neanderthals in underground world

Given the distant from entrance cave to the presence of stalagmites, approximately 300 yards deep, it dated back to the presence of earliest human species because no modern human existed during the era. Moreover, the stalagmite structures are quite deep and difficult to access. Archaeologists believe that Neanderthals must have been very familiar with underground world.

47,600 years old bear bone finding leads to the presence of Neanderthals

Archaeologist Francois Rouzaud, who used carbon dating methods to determine how old the burnt burn is. It is estimated that the bone in the deep dark cave could be 47,600 years old and given the presence of the fossils, the activities inside the cave could be done long before cave painting existed. This is what leads to the earliest human species, Neanderthals.

The problem with Rouzaud's technique is its limit of predicting accurately, only for samples not older than 50,000 years old. According to stalagmite expert, Sophie Verheyden from Royal Belgian Institute of Natural Science, thought that the stalagmites in the cave should be studied as well. She describes the mineral formation as magical structures.

Uranium series dating method

The collective work of researchers using uranium series dating technique finds that there are two rings structures. They are certain that the formations were built by humans' hands by breaking off the cave floor and arranging them into circle structures; four piles in round shape with height up to 15 inch. Researchers also find that when the pieces gathered could weigh more than 2 tons.

The samples are said to be build around 176,000 years ago, CNN has learned. Scientists believe that Neanderthals constructed the formation in Middle Paleolithic century albeit the use is still unknown.

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