Flutterby™! : 176,500 year old fire and rock structures

Fire and rock structures: A Shocking Find in a Neanderthal Cave in France

After drilling into the stalagmites and pulling out cylinders of rock, the team could see an obvious transition between two layers. On one side were old minerals that were part of the original stalagmites; on the other were newer layers that had been laid down after the fragments were broken off by the cave’s former users. By measuring uranium levels on either side of the divide, the team could accurately tell when each stalagmite had been snapped off for construction.

Their date? 176,500 years ago, give or take a few millennia.