Irish Historical Mysteries: Newgrange and Knowth


Newgrange and Knowth are two of Europe's finest megalithic monuments, and although they have generally been described as 'passage-graves', we will be questioning this narrow description. Newgrange and Knowth, together with the still unexcavated companion monument at Dowth and many smaller 'satellite' monuments, are located about 5 miles from the village of Slane, Co Meath, near the River Boyne. Ireland is particularly rich in these monuments, others being found at Loughcrew, Co Meath and Carrowmore, Co Sligo, and in Europe examples may also be seen in Brittany, Portugal and Spain. Many of these monuments contain rock carvings termed 'passage-grave art', and again we will be examining the possibility that these carvings may have had symbolic meanings. (1)

Newgrange is in effect a large mound of stones of various sizes, surrounded by kerbstones and faced with white quartz, and there is also an outer circle of standing stones. The entrance is behind a striking decorated stone, and a narrow passage leads to a cross-shaped chamber. Several of the kerbstones are also decorated, and there are also some internal decorations. Newgrange has been dated to about 3,200 BC, which means that it is about 5,000 years old, older than the Pyramids of Egypt. It must be emphasised that Newgrange as we see it today is essentially a reconstruction following archaeological excavation. Knowth is constructed similarly to Newgrange, but is somewhat older, and contains two inner chambers and a range of inscribed stones far in excess of those at Newgrange. A Boyne Valley Visitor Centre has recently been opened, and it would appear that the increasing numbers of visitors will be catered for through 'virtual' experiences, in order to conserve the monuments proper.

Although Newgrange in time became overgrown and obscured, the memory of the monument appears to have survived in legend as Brú na Bóinne. Newgrange was rediscovered in 1699, and antiquarians first ascribed it to the Danes, radically underestimating its age. The eighteenth-century antiquarian, Charles Vallancy, called Newgrange the 'Cave of the Sun', and while his astronomical theories have been ridiculed, his surveying skills and identification of crucial features of the monument are now securing more recognition.

Newgrange is so oriented that on the morning of the winter solstice on December 21st, and for a number of days before and after, the rays of the rising sun illuminate the inner chamber. This phenomenon was apparently first rediscovered sometime in the late nineteenth century, following additional clearance work and opening up of the inner chamber. Although this remarkable occurrence is now almost universally regarded as having been carefully planned by the builders of Newgrange, archaeologists were among the last to accept this as fact, and indeed there may be a few who still do not. Thus as recently as 1964, Ó Riordáin and Daniel could scoff at a popular account incorporating a reference to the sunlight phenomenon at Newgrange, describing it in total as 'an example of the jumble of nonsense and wishful thinking indulged in by those who prefer the pleasures of the irrational and the joys of unreason to the hard thinking that archaeology demands'. (2)

Fortunately, not all archaeologists were so closed-minded, and between 1967-70 Professor Michael J O'Kelly, who was in charge of excavations at Newgrange, made careful observations which confirmed that at winter solstice, weather permitting, sunlight entered the passage and chamber via a roofbox specially contrived by the original builders. There has been a certain amount of criticism of the excavation and reconstitution of Newgrange, which was performed in accordance with the accepted archaeological practice of deconstructing in order to understand. Nevertheless, the fact remains that O'Kelly was aware of the precise and delicate alignment of Newgrange and of the sunlight phenomenon, and was careful to retain these features in the reconstituted monument.

But could the entry of the sun's rays into Newgrange at winter solstice be a mere accident, resulting from a chance alignment, or worse still, from an unwitting alteration of the entrance during reconstruction? Here again O'Kelly took the precaution of double-checking, and asked a surveyor, John Patrick, to investigate the phenomenon. In an important article published in 1974, Patrick concluded that the orientation of Newgrange must have been arranged deliberately by its builders, that the sun had shone down the passage to the inner chamber ever since its construction some 5,000 years ago, and that it would continue to do so indefinitely. (3)

There have been consistent, and the writer believes, unjust efforts to consign to the realm of pseudo-science the theories of Martin Brennan, the Irish-American author of two books on Newgrange and other megaliths. (4) Brennan claimed, no doubt over-confidently, to have deciphered the rock engravings at Newgrange, as well as the even more numerous and remarkable engravings on the companion monument at nearby Knowth. More sensationally, Brennan also declared that the two back-to-back chambers at Knowth were precisely aligned to receive the sun's rays at the spring and autumn equinoxes, about 20 March and 22 September respectively. Brennan also questioned the archaeologists' description of Newgrange, Knowth and similar monuments as 'passage-graves' or 'tombs', arguing persuasively that they must have had a much wider range of functions, being in effect temples for ritual-astronomical observation.

The discovery in 1969 by O'Kelly - or rather, as we have seen, confirmation of local lore - that a beam of sunlight illuminated the chamber of Newgrange around the time of the winter solstice, should have placed firmly on the agenda of archaeologists the study of directed natural light beams within neolithic passage mounds. Yet while Eogan conceded that the sun or other celestial bodies may have influenced orientation of some mounds, it is not clear that the possibility of a light phenomenon similar to Newgrange has been systematically investigated in the case of Knowth, for example.

It has now become clear that Knowth is an even more fascinating monument than Newgrange, containing as it does not one but two chambers, and holding on its site the remarkable total of one-quarter of the known megalithic art of Europe. Brennan's claim that the two back-to-back passages at Knowth are aligned to both the sunrise and sunset and are designed to receive beams of light at equinox is testable, and if proven wrong, so be it. But if Brennan is right and no testing takes place, proper account may not be taken of this feature during reconstruction, and an opportunity to better understand the monument and its engravings may be lost. Brennan suggested also that Knowth's chambers may have been aligned to receive moon beams as well as sunlight, and that lunar images appear on some of the inscribed stones. It is ironic also that testing Brennan's 'pseudo-scientific' theories involves no alteration or damage to monuments, whereas 'scientific' archaeological excavation may involve irreparable loss of original features, and indeed the long excavation of Knowth appears to the writer to have been little short of vandalisation.

The failure of archaeologists before O'Kelly to recognise the precise astronomical alignment of Newgrange and the intended entry of a beam of sunlight was undoubtedly a major blunder. Those inclined to reject Brennan's theories out of hand should be given pause for thought by the already mentioned scoffing dismissal by Ó Riordáin and Daniels of the popular belief in the sunlight phenomenon at Newgrange. Unfortunately, there is still an unwillingness on the part of many archaeologists, and possibly inability, to consider adequately astronomical interpretations of passage mound engravings. A further puzzling tendency is the insistence that these mounds were primarily designed as tombs, despite the admitted absence of clear evidence for large-scale burial. Because he is a general historian, the writer approached two archaeologists for clarification of these matters, but was met with refusal to comment in one case, and in the other an arrogant rudeness which he confesses he had never before experienced in a scholarly exchange. Live coverage of the Newgrange Winter Solstice phenomenon on 21 December 1999 was by all accounts one of the great missed opportunities in the history of the Irish state media company, Radio Telefís Éireann. In the course of this much heralded world broadcasting event, a veritable babel of politicians, archaeologists, poets, singers and miscellaneous pundits conspired to obscure the beauty and meaning of the event, while the handful of people who could have provided some enlightenment were left outside the monument and the studios literally in the cold.

Although most archaeologists have either ignored Brennan or referred obliquely to him via denunciation of 'pseudo-scientific theories', there have been signs in recent years that some archaeologists at least are prepared to adopt a less hostile attitude. Quite a few are quietly dropping their die-hard opposition, are trying to come to terms with the developing discipline of archaeo-astronomy, and without admitting Brennan's influence, are conceding that the term 'tomb' should not be taken too literally in describing passage-mounds. It is allowed by some that at least one of the engraved stones at Knowth, kerbstone 15, could have been constructed as a sundial, while Elizabeth Shee Twohig has stated that Knowth was also oriented so that sunlight could enter its chambers at particular times of the year. (5) Younger archaeologists are, or should be showing signs of awareness that the destructive excavation techniques they have been taught should be moderated through the use of new surveying and probing technology and computer simulation. Powerful support for some of Brennan's theories has been provided by a dramatic series of time-lapse photographs in a work by Tim O'Brien. (6) Philip Stooke has reinforced and developed Brennan's claims that some of the decorated stones at Knowth display lunar images, stating that these inscriptions are in effect the oldest known lunar maps. (7) Mention should also be made of the work of Frank Prendergast of the Department of Surveying, College of Technology, Bolton Street, Dublin, who has used computer simulation to study the orientation of stones at Newgrange. (8)


Kerbstone 15 at Knowth, stated by Martin Brennan to be a sundial, but have archaeological
excavators rigorously tested this and other archaeo-astronomical hypotheses?


As a matter of urgency, tests for directed sun and moon rays within the inner chambers are required at Knowth, similar to those carried out by Professor O'Kelly at Newgrange. There are increasing grounds to question the hypothesis that ancient rock engravings are essentially either meaningless decorations or anthropomorphic representations. Failure to test Brennan's theories concerning light focussing and astronomical imagery may be impeding the quest to understand the unnamed neolithic peoples who built Newgrange, Knowth and other megaliths. Detailed comparative knowledge of the calendrical systems of ancient civilisations in Europe, the East and the Americas, which frankly few if any Irish archaeologists appear to possess, would be required to test the possibility that megalithic engravings encapsulate astronomical information. Finally and most importantly, the programme of excavation and reconstruction at Knowth should be re-evaluated to take account of the probability that what is being investigated is not merely a tomb, but a still-functioning delicate instrument for ritual-astronomical observation which should not be altered needlessly by one iota.

Knowth eastern passage entrance blocked by concrete slab

STOP PRESS: The Irish Edition of the Sunday Times, 22 October 2000, reports that archaeologists employed by the State have blocked off the eastern passage at Knowth with a concrete slab: There is no justification for this action, which is merely the latest in a long line of acts of vandalisation. For further details and an on-line appeal to the Government, go to Exclusive photographs by Anthony Murphy of equinox sunlight entering the western passage at Knowth can be seen at



(1) The principal archaeological accounts of Newgrange and Knowth are respectively M J O'Kelly, Newgrange: Art and Legend, London 1982, and George Eogan, Knowth and the Passage Tombs of Ireland, London 1986.

(2) S P Ó Riordáin and Glyn Daniel, Newgrange and the Bend of the Boyne, London 1964, page 19.

(3) J Patrick, 'Midwinter Sunrise at Newgrange', Nature, 249, 1974, pages 517-19.

(4) Brennan, The Boyne Valley Vision, Portlaoise 1980, and The Stars and the Stones, London 1983.

(5) Elizabeth Shee Twohig, Irish Megalithic Tombs, Princes Risborough 1990, page 45.

(6) Tim O'Brien, Light Year Ago, Dublin 1992.

(7) Philip J Stooke, 'The Lunar Maps of Knowth', .

(8) Frank Prendergast, 'New Data on Newgrange', Techology Ireland, March 1991, pages 22-25.

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