Banner: sunset over Knocknarea.
The bend or kink in the west passage of Knowth, which may mark the point where the passage was extended, contains a section with a wonderful collection of engraved stones or megalithic art.

Irish megalithic art

One of the best known features of the Irish Passage Graves are the neolithic engravings, a mysterious symbolic language that ornaments many structural stones, especially in the Boyne Valley and at Loughcrew in County Meath. These engravings may be considered the earliest writing or inscription in Ireland, carved by descendants of the first colonizing farmers who landed in County Sligo around 4,150 BC.

It is now accepted that the early farmers migrated to Sligo from Brittany, an area with a long tradition of monument building with megalithic art found at sites such as Gavrinis, Kercado and La Table des Marchands.


A number of early carvings have been found in the western sites of Carrowmore and Carrowkeel. Art was noticed at Listoghil, the central monument at Carrowmore, by tour guide Michael Roberts, which was subsequently published by Patricia Curren Mulligan. The engraving consists of three joined arcs or 'rainbows' carved on the right edge of the huge capstone. To the right of the arcs there is a double ring with a dot at the center.

Martin Brennan.
American rock art expert Martin Brennan visits Carrowmore 51 in County Sligo. The art is digitally highlighted; it is only visible during sunny afternoons during midsummer.

Because the carving is on weathered limestone, it is difficult to see with the naked eye; however, it can be viewed at noon during the summer months when the sun is directly overhead.

This monument, dated to around 3,600 BC, has an astronomical alignment towards the sunrises and moon rises over the peaks of the Ballygawley Mountains six kilometers to the southeast. The modern reconstruction has restricted the view to a few days in late October and early February.

Sunrise at Samhain illuminates the chamber of Listoghil.
Sunrise at Samhain viewed from within the chamber of Listoghil, the darge focal dolmen at Carrowmore.

A series of double arcs on the edge of the capstone seems to represent the peaks of the Ballygawley mountains to the south east. A ring with a dot to either side of the arcs could represent the sunrises at Samhain and the Winter solstice.

Megalithic art from the capstone of Listoghil may be a representation of the sun rising over the Ballygawley mountains, an event which occurs twice every year
Megalithic art on the capstone of Listoghil may be a representation of the sun crossing over the Ballygawley mountains, a journey marked by Samhain, the winter solstice and Imbolc every year.


The sunken megalithic chamber at Cloverhill, 500 meters east of Carrowmore, was discovered during extensive ploughing in 1830. Great excitement ensued when several of the chamber stones were found to be covered with engravings, and George Petrie used the discovery

to connect the period of the erection of this remarkable group of monuments with those of the same class in other parts of Ireland, and particularly with those of the great pagan sepulchres on the banks of the Boyne

Modern researchers believe that the carvings at Cloverhill belong to the late Bronze age Iron age and are probably contemporary with the carving found within the chamber of Listoghil, which was carved with an iron chisel.

A page on Cloverhill from Borlase's Dolmens of Ireland, 1895.
Art from Cloverhill in Borlase's Dolmens of Ireland, 1895.

Heapstown and Carrowkeel

Two more examples of megalithic art were discovered in recent years, one on a kerbstone at Heapstown, the huge unopened cairn at Lough Arrow, the other in the chamber of Cairn B at Carrowkeel.

Heapstown Cairn, County Sligo.
Kerbstone with engravings at Heapstown Cairn in County Sligo.

The discovery of megalithic art at Heapstown, made by the author in the late 1990's was not surprising, as there were rumours of a stone bearing art having been removed from the cairn during quarrying. In some versions the stone was carved with ogham, a script much later than the megalithic art, and stood at the summit of the great cairn. However, the illustration of the designs was drawn by Vincent Dodd in his report for the National Schools Folklore Collection in the 1930's has all the hallmarks of genuine megalithic art.

Heapstown Cairn, County Sligo.
Engravings at Heapstown Cairn in County Sligo. Illustration by Vincent Dodd, National Schools Folklore Collection, 1930's.

The remaining carving is found on a south facing kerb stone and consists of a number of parallel lines, which may indicate that the as yet undiscovered entrance to the monument is close by.

Moonrise viewed from Queen Maeve's cairn in County Sligo. It is highly likely that Irish passage-grave art is a recording of astronomical cycles and events made by the Breton farmers after they had settled in Ireland for a period of time.

Carrowkeel Art

The first piece of engraved art to be found in Carrowkeel was discovered in 2009 by Robert Hensey, who noticed two faint spirals carved in the chamber of Cairn B. An account of the discovery titled Once Upon a Time in the West was published in 2012. These discoveries of megalithic art connect the sites at Lough Arrow and Carrowmore to Loughcrew and the Boyne Valley. As Robert Hensey puts it:

As a result of these new finds there is now megalithic art known from all four major passage tomb complexes. While there seems to be a tradition of making megalithic art at passage tombs in County Sligo, it would be wrong to expect large undiscovered quantities of art in the north-west. The authors carried out a two-week search as part of the Carrowkeel Passage Tomb Art Project at many other passage tombs in the Carrowkeel-Keashcorran complex and a number of other passage tombs in the region, and the second stone in cairn B was the only additional art found.

It is likely, however, that more art will be discovered in the west in time. The possible use of pigments to make colored motifs and designs might also explain the smaller quantities of carved art on passage tombs in the west. Evidence of the use of colour has recently been discovered on the parietal walls at Barnenez and Gavrinis passage tombs in Brittany, France, and at the Neolithic Ness of Brodgar site in the Orkney Islands. It may be that similar evidence will one day be found on the walls of passage tombs in Carrowkeel and on Neolithic monuments elsewhere in Ireland. But that, as they say, is another story.

Conclusion from Once Upon a Time in the West.

Neolithic art discovered in 2009 within Cairn B at Carrowkeel in County Sligo.

There are several other examples of megalithic art to be found at isolated monuments in the mid north of Ireland. The large chamber at Knockmany in County Tyrone has a fine collection of six engraved stones, now covered by a strange glass structure for the protection of the art. The chamber is five meters in length and opens to the south, quite possibly aligned to Loughcrew 80 kilometers away.

Details of the engravings can be viewed at the Megalithic Art Analysis Project page, which also has details on accessing to monument. Another engraved monument is found close by at Sess Kilgreen, where apparently the carvings have eroded badly from exposure to weathering.

Knockmany, County Tyrone.
Knockmany, County Tyrone.

These engravings may well deal with ritual astronomical themes, demonstrated at several sites where the artwork is illuminated by the light of the sun or moon at a chosen time during the cycle of the body in question.

The entrance to Newgrange by Robert Welch.
An early image of Newgrange by the Belfast photographer Robert Welch. A path has been worn to the roof-box stone above and behind the Entrance Stone.

Loughcrew - Sliabh na Cailleach

When it comes to megalithic art, no other place in Ireland can compare to County Meath, where there are more engraved stones than the total for Western Europe.

Equinox sunrise at Loughcrew.
Equinox sun illuminates megalithic art at Cairn T in Loughcrew.
Equinox sunrise at Loughcrew.
Later in the same sequence.

Knowth alone has 50% of the engraved stones in Ireland. Early engravings have been discovered in recent years on the chamber of Listoghil monument at Carrowmore in Co Sligo. Heapstown Cairn, also in Sligo is known to have had several engraved stones, with perhaps an ogham stone standing at the top of the mound. Only one stone remains visible today, as many were robbed from the site in the last century.

The cosmic designs within the right recess of Cairn L at Loughcrew has echoes of the pattern on the huge basin within Knowth east.

Few designs are known in the west of Ireland and some other scatters sites such as Knockmany and Sess Kilgreen in County Tyrone. Loughcrew, just within the west boundary of County Meath has many engraved stones, of a type that seem rougher and earlier than the art of the Boyne Valley. Many of the engravings are badly weathered from long exposure to the elements, while those that had shelter are as fresh as the day they were engraved more than 5,000 years ago. Loughcrew retains two fabulous alignments where the rising sun illuminates and interacts with the panel of art at Cairns T and L.

Decorated stone in the mid left recess of Cairn I at Loughcrew. The rain helped show up the art. Note the vivid red blotch on the stone behind - the result of weathering?
Neolithic art on a passage stone within Cairn F on Carnbane west. Zig-zags, undulating waves and diamond shapes, the latter thought to be ancient units of land measurement by researchers Martin Brennan and Michael Poynder.
Knowth Basin.
The Great Basin of Knowth in the Boyne Valley.

The Boyne Valley

The so called Guardian stone or Owl man at the bend in the passage of Knowth west. The neolithic art is deeply scratched, probably by the later medieval graffiti artists who left at least 20 ogham names on the stones of Knowth.
Large and beautiful panel from a roof stone in the passage of Knowth east.
This stone was found lying in the medieval ditch that encircles the mound of Knowth, and was restored as a passage stone during the 'restoration'.
This kerbstone from Knowth may be a representation or diagram of the nearby mound at Newgrange.
Decorated cairn stones from Newgrange.
Decorated cairn stones from Newgrange.
The Great Basin of Knowth.
The elaborately decorated roof stone in the end recess of Cairn T at Loughcrew. Note the spiders and the eight-spoked designs. This panel is brightly illuminated by reflected sunlight on the equinoxes.