Trephination, or trepanning, is often said to be the oldest known surgery; it goes back at least 8,500 years. Scientists found 120 stone age skulls in France, 40 had holes in them.

Originally released by Smithsonian Media, 2014. Streaming video file encoded with permission for digital streaming by Infobase on March 10, 2015.

Do People Really Drill Holes in Their Heads?: Ask Smithsonian (1:00); .