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Cairn L.
Cairn L is not unlike a space ship taken from this angle with a huge lens, by Padraig Conway.

Astronomy at Cairn L

The most unusual aspect of this wonderful monument is the presence of a tall pillar stone within the chamber known as the Whispering Stone. This slim striking limestone pillar, rectangular in section, is over 2 meters tall. One gets the impression that the chamber and cairn were constructed especially to house this stone; as Cairn L seems to have been built after it's satellites, perhaps the Whispering Stone was free-standing for many years. The only other known example of a standing stone within a neolithic chamber of this type known so far is the buried stone within Cairn F at Carrowkeel, which is oriented due north.

Conwell's illustration of the Whispering Stone and large basin in the right hand recess of Cairn L. From about 1870.
Conwell's illustration of the Whispering Stone and large basin in the right hand recess of Cairn L. From about 1870.

The mystery of the Whispering stone is added to by the orientation of the chamber. There is a skew or slight bend in the remaining section of the passage of Cairn L. There seem to be several meters of passage missing up to the modern reconstruction from the 1940s.

Standing in the back recess, the chamber seems to be aligned to a notch between two distant hills between Carnbane and Sliabh Rua, well to the left of the alignment illustrated below. The alignment of this passage may have been altered a few times before it was destroyed.

The entrance of Cairn L, with its tall sillstone.
The entrance of Cairn L, with its tall sillstone.

During their research at Loughcrew, Martin Brennan and Jack Roberts discovered that the sun illuminates this chamber on the mornings of Samhain and Imbolc, during the first week of November and the first week of February, the ancient cross-quarter days. Though this may not be the original alignment we are still left with a spectacular display of sunlight illuminating megalithic art.

Trial excavation or resistvity surveying in front of the entrance for empty sockets could tell us how the entrance looked before it was damaged.

Sunrise over Cairn M
Early November/Samhain sunrise over Sliabhrua or Carrigbreac( Cairn M ). Cairn T is just visible as a bump at the extreme left of the photo.

The Whispering Stone

As the sun rises over Sliabh Rua, which is also called Carrick Breac - the Speckled Rock, the beam flashes dramatically into the chamber and strikes the top of the Whispering Stone. As the sun rises higher in the sky, the beam of light slips off the standing stone and into the large right-hand recess, which contains the massive stone basin and a finely decorated chamber stone. The beam of light is very bright in the darkness of the chamber and brilliantly illuminates the engravings - see photographs below. It would seem that the monument and chamber were constructed around this mysterious stone.

A rubbing of the engravings in the right hand recess by Elizabeth Twohig.
A rubbing of the engravings in the right hand recess by Elizabeth Twohig from her book, The Megalithic Art of Western Europe, which has a record of all the visible art at Loughcrew.

Brennan and Roberts also observed the full moon entering and illuminating the end recess of Cairn L on the 26th August 1980. The moon struck a cupmark on the endstone, and then moved to the right to illuminate the bottom of the Whispering Stone. Little observational research has been done on the movements on the moon in these monuments.

The photographs below, part of a set taken on a very cold November morning show something of the movement of the Sun within the right hand recess.

Sequence of sunbeam within chamber of Cairn L, 8 November 1995. The light source it the sun; camera: canon slr, no flash, fuji slide film.

Light enters the chamber, illuminating the passage orthostats.
1. Light enters the chamber, illuminating the passage orthostats, this one with massive amounts of graffiti.
The sun dramatically strikes the top section of the Whispering stone.
2. The sun dramatically strikes the top section of the Whispering stone.
Cairn L photographed by William Green.
Cairn L photographed by William Green.

Solar Illumination

The sun has just moved off the Whispering stone and into the back of the recess.
3. The sun has just moved off the Whispering stone and into the back of the recess. The panel of light is now the same shape as the doorway. You can see the Whispering Stone, bottom left.
The beam of light, reflecting off the end of the recess, is strong enough to fully illuminate the engravings.
4. The beam of light, reflecting off the end of the recess, is strong enough to fully illuminate the engravings.
The sunbeam moves towards the small white stone in the corner.
5. The sunbeam moves towards the small white stone in the corner.
The sunbeam begins to shrink as the sun rises higher in the sky.
6. The sunbeam begins to shrink as the sun rises higher in the sky.
Last light: the beam breaks up as the sun leaves the chamber.
7. Last light: the beam breaks up as the sun leaves the chamber. The whole process lasts about 20 minutes.

This monument has been closed to the public for a number of years now, and this sequence of images is one of the few that exist documenting this amazing alignment. To view the chamber of Cairn L, special permission is needed from both the landowner and the OPW.

View from Cairn M at Loughcrew
The view of Cairnbane West from Cairn M on the summit of Sliabh Rua or Carrig Breac. The massive Cairn D is to the left, and Cairn L is to the right. Bealtine and Lugnasadh cross quarter day sunsets will drop behind Cairn L from this position.