Bronze Age skull from Jericho, Palestine, 2200-2000 BC. Although this skull shows four separate holes made by the ancient surgical process of trepanation or trephination, they had clearly begun to heal. This suggests that although highly dangerous, the procedure was by no means fatal. Also known as trepanation, or trepanning, the process of making a hole through the skull to the surface of the brain might be carried out to treat a range of medical conditions or for more mystical reasons. The skull was excavated from a tomb in Jericho, in January 1958.