Neanderthals Likely Built These 176,000-Year-Old Underground Ring Structures

About 40,000 years before the appearance of modern man in Europe, Neanderthals in southwestern France were venturing deep into the earth, building some of the earliest complex structures and using fire. That's according to new research that more precisely dated bizarre cave structures built from stalagmites, or mineral formations that grow upward from the floor of a cave. Scientists discovered about 400 stalagmites and stalagmite sections that were collected and stacked into nearly circular form