Newgrange sits in Ireland's Boyne Valley, about 30 miles north of Dublin. Built around 3200 B.C., this massive stone monument features a long passage leading to a central chamber, all covered by a circular mound of earth and stones. For over 300 years, treasure hunters and antiquarians ransacked the site, making it nearly impossible to know exactly where artifacts originally came from.This historical looting creates a major problem for the "king" theory. The skull fragment NG10 was found during proper archaeological excavations in the 1960s, but researchers can't definitively say it was originally placed in the tomb's supposedly "prestigious" right-hand...