¹O'Grady, Standish. Early Bardic Literature. London: Sampson Low, Searle, Marston & Rivington, 1879. 77-78.

²The two tombs within the Dowth mound are not (in 2011) considered secure and are closed to visitors, except for the yearly opening of the south tomb for the winter solstice sunset. A 2006 winter solstice photograph by Clare Tuffy (OPW) shows the people gathered for sunset standing high on the mound to catch the last rays of the setting sun. Information regarding the annual opening of the tomb for the winter solstice sunset may be found here. There was previously access available to the north tomb through the souterrain tunnel, in total darkness. An account of such a visit is available here.

³Herity, Michael. Irish Passage Graves: Neolithic Tomb-builders in Ireland and Britain, 2500 B.C. New York: Barnes & Noble, 1975. 3.
The 1847-48 excavation report estimated the effort required: "When perfect, the cubical content of the whole may be estimated at about 75,000 Cubic Yards, & considering the probable means then available for performing such work, 6 men would be required to collect & place the materials of each Cubic Yard in a day, so that the formation of the Mound itself, without any reference to internal Chambers, would require the labour of nearly half a million of men for a day, when we consider the remote period at which this must have been executed, the limited number of men which could then have been procured for the purpose, the great difficulty of transporting such bulky materials to a distance as those stones surmounting the bank composing the chambers of the Mound, & the consequent great length of time which must have been consumed in the creation of the work, even this apparently rude structure will bear a favourable comparison with some of the more celebrated works of modem times." (O'Kelly, M.J., Claire O'Kelly, V.R. O'Sullivan, and R.H. Frith. "The Tumulus of Dowth, County Meath." Proceedings of the Royal Irish Academy 83C (1983): 1586-88.)

⁴Dowth, Brú na Bóinne. 2 June 2010. Information sign at the site. Dowth.
The "Stone of the Seven Suns" is considered in the context of its "ancient astronomical symbolism" here. Other sources for discussions of the rock art at Dowth include:
Coffey, George. "On Stone Markings (Ship-Figure) Recently Discovered at Dowth, in the County of Meath." Proceedings of the Royal Irish Academy 4 (1889-1901): 586-88.
Coffey, George. "On the Tumuli and Inscribed Stones at New Grange, Dowth, and Knowth." The Transactions of the Royal Irish Academy 30 (1892/1896): 51-67.
O'Kelly, M.J., Claire O'Kelly, V.R. O'Sullivan, and R.H. Frith. "The Tumulus of Dowth, County Meath." Proceedings of the Royal Irish Academy 83C (1983): 158-59.

⁵O'Kelly, M.J., Claire O'Kelly, V.R. O'Sullivan, and R.H. Frith. "The Tumulus of Dowth, County Meath." Proceedings of the Royal Irish Academy 83C (1983): 148-56.
It was the urge to find a major central burial chamber at Dowth that prompted the ill-considered and poorly-executed 1847-48 excavations.

⁶Moroney, Anne-Marie. "Winter Sunsets at Dowth." Archaeology Ireland 13.4 (1999): 29-31.
Photographs taken demonstrating the illumination of the south tomb during the sunset of the Winter Solstice may be seen here and here.

⁷Cooney, Gabriel. "Dowth Passage Tomb." Archaeology Ireland 11.3 (1997): 18.
Coffey reported that "The present chamber roof is of concrete and is noticeably less successful at keeping out the rainwater than the Newgrange roof built about 5000 years ago." (O'Kelly, M.J., Claire O'Kelly, V.R. O'Sullivan, and R.H. Frith. "The Tumulus of Dowth, County Meath." Proceedings of the Royal Irish Academy 83C (1983): 148-56.)

⁸Eogan, George, and Eoin Grogan. "Prehistoric and Early Historic Culture Change at Brugh Na Bóinne." Proceedings of the Royal Irish Academy 91C (1991): 118.

⁹"Part 432 of The Annals of Ulster." UCC Home Page. Web. 29 June 2011. <http://www.ucc.ie/celt/published/T100001A/text432.html>.

¹⁰O'Kelly 136-41.
Michael Herity has noted, "Passage Graves, probably because they often commanded a good view, seem to have been fairly often chosen as the sites of follies. Professor Ruaidhri de Valera has pointed out to me that the circular structure at the top of Clermont cairn in Co. Louth is probably the remains of one." (Herity, Michael. "From Lhuyd to Coffey: New Information from Unpublished Descriptions of the Boyne Valley Tombs." Studia Hibernica 7 (1967): 142, note 24.)

¹¹O'Kelly 136-41.
Penal Law, in effect at the time, would have made it difficult for Netterville to practice his Catholicism openly.

¹²O'Kelly 41-44.
All the artifacts recovered from Dowth date to its period of use in Early Christian and Norse times. The 1847-48 excavation discovered burned bones, some human, within the chamber of Dowth North. In 1970, Claire. O'Kelly found a human mandible just beneath the surface of the floor in Dowth South.

¹³O'Kelly 141-44.

¹⁴O'Kelly 144.

¹⁵O'Kelly 147-48.

¹⁶Gwynn, Edward, trans. The Metrical Dindshenchas: "Cnogba." Cork: CELT: Corpus of Electronic Texts, 2004. The Metrical Dindshenchas. University College, Cork. Web. 29 June 2011. <http://www.ucc.ie/celt/published/T106500C.html>. 45.

¹⁷Gwynn 43-47.