Now on the banks of the Boyne, opposite Rosnaree, there stands a tumulus, said to be the greatest in Europe. It covers acres of ground, being of proportionate height. The earth is confined by a compact stone wall about twelve feet high. The central chamber, made of huge irregular pebbles, is about twenty feet from ground to roof, communicating with the outer air by a flagged passage. Immense pebbles, drawn from the County of Antrim, stand around it, each of which, even to move at all, would require the labour of many men, assisted with mechanical appliances. It is, of course, impossible to make an accurate estimate of the expenditure of labour necessary for the construction of such a work, but it would seem to me to require thousands of men working for years.
- Standish O'Grady, Early Bardic Literature, Ireland (1879)