103O'Sullivan, Muiris, Michael Herity, and Ursula Mattenberger. Duma na nGiall: the Mound of the Hostages, Tara. Bray, Co. Wicklow: Wordwell, 2005, p. 7.
Although before its late-1950s excavation it was not known that the Mound was a passage tomb, there were suspicions. The authors quote Seán P. Ó Ríordáin in 1953: "the form of the mound 'shows it to be a burial mound, such as might be of almost any date in prehistoric times.'"