In recent years, there has been intense debate over specific structural details in the reconstruction of the passage tomb of Newgrange.
One headline in the Irish Times (21 December 2016) sums up the claims:
Trapping the winter solstice sun at Newgrange in Co Meath is not a 5,000-year-old phenomenon, but a 50-year-old “construct”, according to a former State archaeologist.
For an excellent and detailed rebuttal of the campaign against O'Kelly's findings, read this article by Ken Williams:
http://boynevalleytombs.wordpress.com/2019/04/14/re-discovering-the-lost-records-of-the-newgrange-roof-box/?fbclid=IwAR0bkcc5IFg5DnW5tAfQ2OJDSRf9Cpfcjbmv3Rl_Fk66qEzzMI3U9PQBjDk