"We compared the site where broken pottery had been plowed during farming with the magnetometer map, which showed large cavities one to two meters below the surface. This led us to continue investigating the area and to discover the tombs."
repulsewarrior wrote:40 to 50 thousand years ago, beautiful round holes; how did they do it?
There is a way of creating such holes. I suspect this method was used with some variation to create the hole in bow drilling. All you need to do is attach a hard stone at the end of the spindle and bob's your uncle.