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 Newgrange Light-box.     Light-boxes:

 Light-boxes are an exclusively Neolithic design feature employed so as to restrict the entrance of light into a chamber or passage.

This particular construction feature has so far only been recorded at four (possibly five) sites in the Britain, with the two in Ireland (Newgrange and Carrowkeel) both having the same design, two on the Orkneys (Maes Howe and Crantit) in Scotland and one in Wales (Brynn-Celli-Ddu).

Newgrange at the Boyne Valley (right), possesses the finest known example of a 'Light-box'.


The incorporation of light boxes into megaliths is one of the few direct proofs of the link between megaliths and astronomy, as their purpose was the manipulation of light into the passage mounds at certain times of the year only. In Egypt, the earliest pyramids all contain 'polar-shafts', on Malta, the 'Temples' orientated towards the solstices and equinoxes and in Britain, all the known passage-mounds containing light-boxes were also  aligned with solar events, (i.e. the equinoxes or solstice)


At present there are only four (possibly five), known examples of 'light-boxes', all in European megalithic structures (passage-mounds). Their design permits a focused beam of light from prominent celestial objects such as the sun and moon, to enter the chamber at specific times of their cycles. The most famous of these is at Newgrange in Ireland, where the light-box allows the suns rays to pass along the passage into the heart of the mound on the winter-solstice sunrise, (and possibly, one of the major lunar stand-stills - to be confirmed)...


  • Newgrange - Ireland, (Winter Solstice, Lunar standstill)

  • Crantit Tomb, Orkneys - (start and end of winter..?)

  • Carrowkeel - Ireland, (Summer and winter solstice, Lunar standstill)

  • Maes Howe - Orkneys, (Winter solstice).

  • Bryn Celli Ddu - Anglesey, (Summer solstice, Lunar standstill)


 The Newgrange Light-box.

At Newgrange, the light-box is used along with other construction features (such as the passage narrowing and undulating along it length and a subtle increase in altitude towards the centre),  which combine to focus the rays of the sun along the passage into a small, narrow beam of light, which is visible for only a few minutes on a few days around the winter solstice. As well as illustrating the astronomical nature of the structure, the inclusion of such a specific set of designs highlights the importance of accuracy to the builders.

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Image illustrating the design of the Newgrange passage and chamber (Not to Scale)


The Crossed/Lozenge lintel-stones.

The passage-mound at Gavr'inis has a specific feature in common with at least one other passage mound in Ireland. They both have a stone with a series of 8 (9 - see below), crosses/lozenges on its face in the entrance or passage. This feature has been found at both Newgrange (over the light-box), and at nearby Four-knocks. We already know that Newgrange has been dated at 3,200 B (2), which, when combined with the similar orientation and passage art, lends itself to the idea that they may all be contemporary structures.

Newgrange, East-rear lintel inside the chamber.

Gavrinis sill-stone. Fourknocks lintel, Ireland.

Gavrinis 'Sill-stone' in floor, left. Fourknocks, having three crossed lintels, right.

The drawing on the right was made before the reconstruction of the Newgrange mound. It suggests that the lintel-stone at Newgrange may have had 9 crosses on it rather than the 8 usually quoted. If this is the case, then the stone would be an almost exact match for the stone in the Gavr'inis passage mound (which also has 9 crosses), now in the floor of the passage (where only the tops of the crosses are now visible as a series of 'V's).

The Gavrinis 'Sill-stone' lies across the passage floor in a style similar to the passage mounds in Ireland (such as those at Carrowkeel), where 'sill-stones' are found on the floor, apparently symbolically dividing the internal structure.

It has been noted that this specific design-feature is found on the floors of ocean-going ships.


The passage-mound at Four-knocks has three similar lintel stones, with two in position over the side chambers, and a third at the entrance. The significance of this design can only be guessed at, and the appearance of a similar stone in the contemporary Gavr'inis passage mound lends further weight to the argument for a close cultural contact between the Irish and French Neolithic passage mound builders.

This ochre stone was found in a cave by the sea in Africa with the same markings on it. It is dated at approx. 70,000 BC. (Full article)


Newgrange (left), and Carrowkeel (right).


Carrowkeel: A second Irish light-box has been recently discovered through the research of Martin Byrne, who showed that a Neolithic tomb at Carrowkeel was oriented to the most northerly point the setting Moon reaches on the horizon, an event that only happens every 18.6 years at midwinter. The report suggested that the lunar association had been missed until now because it is only very occasionally illuminated by sunlight or moonlight....

Several mounds at Carrowkeel have features that suggest the possibility of light-boxes:

The Carrowkeel light-box was designed to capture the light of the setting sun at summer Solstice, and the light of the setting moon at the winter solstice and Lunar Extremes.

Cairns H (Right) and D have long box-like kists. Cairns G and K have cruciform chambers and
double-lintelled entrances. This offers the possibility that other passage mounds at Carrowkeel will one day be identified as having 'light-boxes' in their design.

Cairn B has the most commanding position of all the tombs. Within a kerbed cairn 22.5 metres in diameter and 5 metres high is an accessible, fairly-crude pentagonal chamber with two sill-stones at either end of a passage.



 Scottish Light-boxes:

Maes Howe: Orkneys: The light box in the Maes Howe passage mound is different in design to the Irish ones, in that it is a 'moveable' stone, which was built into the original design of the passage. The function of the stone is intrinsically the same. The stone sits in a pre-designed cavity in the corridor, and can be moved at will (The guide said that it had 'rocking' properties). It is triangular in shape, and its design is such that when it is in a 'closed' position, it restricts the entry of light along the passage (whilst leaving a gap at the top for a small amount of light to enter).

The light of the setting solstice sun was restricted by the closing of a 'portal stone', placed into the side of the passage. In this way, at the right moment, the stone could be closed across the passage, and the light would only pass over the top (as at Newgrange). The same design feature is also present in the entrances of the three sub-chambers, each of which also had a blocking-stone which closes most of the hole, but not all of it. (These stones now lay on the floor in front of the holes).


Maes howe portal-stone.

Inside the cruciform chamber of Maes Howe there are three other smaller chambers built into the walls, each of which has its own  smaller version of these partial 'blocking' stones lying on the floor in front of it. Their position makes it fairly obvious that they were each once in the holes that they sit in front of, and their smaller size and triangular shape repeats the design of the 'blocking' stone in the corridor.

(More about Maes Howe)


The Crantit tomb, Orkneys: A possible light-box has been found in the Orkneys, in the underground Crantit tomb after a tractor disturbed a series of flat stones that turned out to be 5,000 year old roof slabs. It was noticed that one of these roof-stones had a notch cut into it which would allow a ray of sunlight to penetrate the tomb in October and again in February (at the beginning and the end of winter) when the Sun would have thrown a shaft of light along the length of the tomb.

Strange carvings were found on the upright stone pillar that holds up the roof. "If you look closely you can see geometric patterns and symbols carved into the rock," Dr Ballin Smith said. And in respect to the 'light-box' we are told that:

The south-east facing section of the cairn appeared to have a notch in the wall. Although it looked like no more than a broken stone, it seemed that the "notch" had been put there deliberately.

The first investigation revealed that the cairn had not actually been covered by a mound, but had instead been dug into the ground. This seemed to indicate that it was never meant to be visible from the surface. This fact marked the Crantit cairn (and the 'light-box') as being hugely unusual. However, the fact that it was both sealed, underground and dubiously orientated casts a doubt on the validity of the 'light-box' as it would only have functioned following the removal of clay and roof-stones, which is not consistent with the design of the two other light-boxes in Ireland.

The following photo's are Before and After photos from Crantit following the second official investigation of the site.


(More about the Crantit tomb, Orkneys)

Note: At the latitude of the Orkneys the major lunar standstills north becomes almost circumpolar, (neither rising nor setting - with the effect that the moon 'rolls' along the horizon). Because the Earth�s axial tilt has changed by nearly half a degree since the majority of the stone circles were built, this effect is no longer accurate and the latitude today would have to be 63� north for a lunar standstill north to be truly circumpolar (10), while a truly circumpolar Moon would have been visible on the Orkneys at around 3,500 BC.

(More about the Orkney Islands)



 The Bryn Celli Ddu 'Light Pillar'.

The Bryn Celli Ddu passage mound does not have a 'light-box' per se, but it does appear to have a sophisticated means of measuring the year incorporated into its design, by restricting the entry of light into the passage at certain times. The design of the entrance and passage acts along with a pillar in  the chamber, as a declinometer by casting a dagger of light on the pillar, which changes height throughout the year. The light which enters the chamber is focused so that it falls almost exclusively on the pillar in question.

At Bryn Celli Ddu, the passage-mound was designed in such a way so as that the light of the sun at relevant times of the year would penetrate the chamber and cause a beam of light to be cast on a 'Declination Gauge' made by the tall, cylindrical pillar placed at the back of the hexagonal chamber.

The changing altitude of the sun over the year causes the light of the sun that reaches the inside of the chamber to move up and down the pillar over the year. Notches have been found which support this theory.


The positioning of the stones at the entrance and along the passage restrict the light into a narrow beam which can be seen to move up and down the pillar over the year.


(More about Bryn Celli Ddu)



 The 'Light-Tube' at Monte Alban, Mexico.

The so called 'Zenith Tube' found in Building 'P' in the centre of the ceremonial centre at Monte Alban acts in essentially the same way as the European 'Light-boxes', allowing a beam of light to pass through a pre-designed 'chimney' built into the structure. These 'Light-tubes' were designed for measuring the moments when the sun passed overhead twice each year on its azimuth.

At the bottom of the light-tube is a large viewing chamber which the sun would illuminate twice each year. The top of the shaft had a small, precisely fitted shaft running directly east which it is believed to have acted as a predictor-gauge for the 'light-tube'.

(More about the Monte Alban 'Light-tubes')

The deliberate precision with which these passages were constructed is extended outwards to the strangest structure at Monte Alban, nearby and also in the centre of the grand plaza is building 'J' or 'The Observatory', with its irregular angled walls and carved stellae, this building is both orientated along its axis towards building 'P', and to the northeast to where the bright star Capella was seen to rise in the processional era of 275 B.C

The fact that both these structures occupy a noticeably central position in the ceremonial mountain citadel, sitting at the centre of the Oaxaca Valley, which was once inhabited by onwards of 35,000 people making it the second largest pre-Columbian city in Meso-America, and second only to Teotihuacan in the north, demonstrates their importance to the Zapotec builders. One or two other examples of 'light-tubes' are known to exist at other Zapotec sites.

(More about Monte Alban)



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