4Jones, Carleton. Temples of Stone: Exploring the Megalithic Tombs of Ireland. Cork: Collins, 2007. 23.
Jones adds, (p. 111) "We know, in fact, that towards the end of the megalith-building period, Neolithic people sometimes built large timber circles for their rituals. Archaeologists also sometimes find the eroded and silted-in remains of large earthen enclosures that date to this slightly later period as well. So we know that Neolithic people were capable of creating monuments with different materials but they chose to use large stones for building the megalithic tombs. Surely this was because the stones themselves conveyed something that was important to the Neolithic builders."