Banner: sunset over Knocknarea.
An old photo of Ireland's largest dolmen at Brownshill in County Carlow.
An old photo of Ireland's largest dolmen at Brownshill in County Carlow.

Irish portal dolmens

There slightly under 200 portal dolmens in remaining in Ireland. They are easliy the most clearly recognisable type of Irish megalithic monument, with Poulnabrone dolmen in County Clare often used in international marketing campaigns. The monuments we call portal dolmens today were known by many different names: Cromleachs, Giants Graves, Leabas or Beds, Diarmuid and Grainne's Bed, Giant's Griddle or Griddlestones and Stone Tables. As they name shows, they were considered to be otherworldly structures, the graves of giants or heroes or fallen warriors. There many fine examples found in Ireland.

Clough portal dolmen, the Trillick of Ballintrillick in County Sligo was destroyed around 1950.
Clough portal dolmen, the Trillick of Ballintrillick in County Sligo was destroyed around 1950.

Dolmens as a monument type are generally classified by a kind of entrance feature, the 'portal' or doorway opening into the burial chamber. This portal or entry is often found closed by a blocking stone. The most chararteristic feature of a portal dolmen is the massive capstone or roofstone, often weighing tens of tons and usually inclined at an angle with the highest portion over the entrance or portal.

How to build a dolmen by William A Green.
How to build a dolmen by William A Green.

Many monuments exhibit the remains of long cairns of stones, and it is believed that the monuments would have been covered with cairns up to the capstone. What we see today is the remaining structures, with the surrounding cairns long since removed for building stones and road materials.

Poulnabrone dolmen in County Clare.
Poulnabrone dolmen in County Clare.

Poulnabrone portal dolmen in County Clare is one of the most familiar and iconic neolithic monuments in Ireland. The chamber may have originally been covered with a cairn of stone, with probably just the massive roofslab visible at the top.


Portal dolmens are often known as Diarmuid agus Grainne's beds in Irish mythological stories and folklore connected with specific monuments. The original Diarmuid agus Grainne's bed is shown in the illustration above from 1837, showing the cave in Gleniff, Benwisken and the old Trillick or dolmen that gives the village of Ballintrillick its name. Many dolmens are also associated with graves of famous giants or warriors, such as Nuada of the Silver Arm in Sligo's Labby rock. Other sites were used by the Fianna and Fionn Mac Cumhail as cooking places or Griddle Stones, especially in west Sligo.

The Giant's Griddle stone,  County Sligo by William Wakeman.
The Giant's Griddle stone, County Sligo.

Wakeman's tasteful illustration of the Giant's Griddle in Tawnatruffan in west County Sligo, above, dates from around 1880, just when photography was becoming more fashionable. The Griddle Stone, a strikingly graceful structure, is one of several in the area associated with Fionn Mac Cumhail and his cooking activities.

These monuments are just across Ballisodare bay from Carrowmore and Knocknarea on the Cuil Iorra peninsula, where more monuments aew associated with Fionn. The standing stone at Tobernaveen was a drinking spot for them, the Kissing Stone at Carrowmore was often called Leaba na Fian, as in the grave of the Giant or Great Warrior. Fionn Mac Cumhal, the chief of them all was said to have been buried at Listoghil at the centre of Carrowmore.

The Kissing Stone, dolmen number 7 at Carrowmore in County Sligo.
The Kissing Stone or dolmen number 7, at Carrowmore in County Sligo.

Most dolmens are thought to have been covered with mounds of stone, but little remains of these cairns at most sites today. The impressive structures we see remaining are like the bones of the original monuments — something like seeing the skeleton of a dinosaur in a museum. They are thought to have been boundary markers between different tribes and areas, and are often found in shallow valleys close to streams.

There are many fine dolmens found all across Ireland. The most famous is probably Poulnabrone at the heart of the Burren in County Clare. Poulnabrone is one of the few dolmens in Ireland to be excavated in modern times. Ann Lynch's excavations uncovered the remains of some 22 people, some of whom had been disarticulated and defleshed as early as 3,800 BC.

The largest capstone is found at the Brownshill dolmen in County Carlow with a massive 100 - 150 ton roofslab. There are eleven dolmens in County Sligo, including the Labby Rock on Moytura, with a 70 ton capstone, the very beautiful Giants Griddle in west Sligo, and the massive Cloghcor in north Sligo.

Poulnabrone dolmen in County Clare.
Probably Ireland's best known portal dolmen, Poulnabrone is found halfway between Kilfenora and Ballyvaughan, at the top of Corkscrew Hill at the centre of the Burren.

Origins of dolmens

Though they are classed as Passage Graves, the early monuments at Carrowmore in County Sligo could be classed as a mixture of several monument types. Many of the stone circles have a dolmen at the centre, Number 7, the Kissing Stone being the best surviving example. Many of the dolmens at Carrowmore are too small for a person to enter, the exceptions being Dolmen Number 7, Dolmen 13 and the cruciform chamber of Circle 27.

Dolmen 13 at Carrowmore.
Dolmen 13 at Carrowmore, County Sligo. The stone circle was destroyed around 1837 when a road was built by this dolmen.

Dolmens 7 and 13 are the largest remaining chambers at Carrowmore, and it has been suggested that these two monuments, which are about 100 meters apart, form a portal or entryway into Carrowmore from the north and northeast, where other neolithic monuments are found at Barnasrahy, Magheraboy, Carns Hill and Lisnalurg.

Though the monuments at Carrowmore appear to be dolmens, they are the chambers of passage-graves, a type of monument appearing in Brittany about 5,500 BC. Irish portal dolmens may well be descended in style and form from the chambers of passage-graves.

The Labby Rock in County Sligo.
The Labby Rock in County Sligo.

Moytura in County Sligo, site of a mighty battle between competing tribes in Ireland's fabled past, has an amazing array of neolithic monuments, including one of the largest portal dolmens in Ireland, the Labby Rock.

Sligo's dolmens.

The Labby Rock, Moytura, Lough Arrow, County Sligo.
The Labby Rock.

The Labby Rock, a massive portal dolmen on the ridge of Moytura in County Sligo, is said to be the grave of Nuada of the Silver Arm. This massive chunk of limestone is thought to weigh some 70 tons. The Labby Rock has some powerful mythology associated with it. It was here that Balor of the Evil Eye killed Nuada of the Tuatha De Danann. The massive rock was raised over his grave.

The Aghacliff dolmen in County Longford.
The Aghacliff dolmen in County Longford.

Marking Territory

Some dolmens may be boundry markers, placed on important ancient territorial land zones. For example, the Labby Rock, above and collapsed dolmen at Highwood nearby, illustrated below, may have been marking off the space overlooked by the cairn at Shee Lugh on the summit of Moytura.

Another large dolmen on Moytura collapsed sometime between the visits of Petrie who illustrated it, above, and Wakeman who found nothing worth illustrating. The site of this collapsed monument has recently been identified. Again, it may be a boundry marker, and a compliment to the Labby on the other side of the ridge.

The Stirring Rock at Carrowkeel.
The Stirring Rock at Carrowkeel, County Sligo.

The Stirring Rock is a very interesting and disturbed monument one kilometer south of Cairn F at Carrowkeel.

The monuments inclide a rocking stone, a megalithic structure: surely some kind of dolmen, several caves and a large erratic boulder known locally as the Dagda's Stone. Local people used to dance around the Stirring Rock on the second last Sunday of July - Bliberry Sunday. The ancient dolmen structure is very interesting: craggy, worn and mysterious.

The Stirring Rock was pushed over at some stage in the 1930's or the 1940's in an attempt by the Catholic church to discourage people from using the monument.

The Tinnacarra dolmen close to Boyle in County Roscommon.
The Tinnacarra or Drumanone dolmen near Boyle in County Roscommon.

The Tinnacarra or Drumanone dolmen near Boyle in Co Roscommon has a monsterous capstone of a similar size and shape to those at Cloghcor, Kilclooney and Malin More in County Donegal. The dolmen is composed of great hoary hunks of sandstone with portals about three meters high.

The capstone has slid down somewhat off the portals. This is an easy monument to locate and access, it is about three kilometers west of Boyle, past a bad bend and across the railway track.

The Malin More Dolmen close to Glencolumbkille in County Donegal; photograph by W. A.Green © NMNI.
The Malin More Dolmen close to Glencolumbkille in County Donegal; photograph by W. A. Green © NMNI.

Cloghcor Druid's Altar

The Druid's Altar at Cloghcor in Co Sligo is located on the summit of a drumlin and commands wide views across the surrounding landscape. The chamber is aligned to the north. The monument is a good place to observe the equinox sunrises, when the sun emerges from the cliffs of Kings mountain.

The Cloghcor dolmen, County Sligo.
The Cloghcor dolmen, County Sligo.

The huge sandstone capstone has slid back off the impressive three meter tall portal stones. In 2020 a panel of neolithic artwork consisting of fourteen cupmarks was discovered by Community archaeologist Tamlyn McHugh and landowner Leo Leydon. This is the first time neolithic art has been discovered on such a monument.

The Fenagh dolmen.
The Feenagh Dolmen, County Leitrim.

The Fenagh dolmen in County Leitrim has a large limestone slab for a capstone and the remains of a long cairn of stone. The dolmen is one of a number of different types of megalithic structure found close together in this area making a small cluster. The other monuments are two or three round passage-graves, a court-tomb, and several standing stones nearby.

The Aghacliff dolmen, County Longford.
Aghacliff, County Longford.

The Aghacliff dolmen in County Longford has an unusual and impressive double capstone, one of the strangest looking dolmens in Ireland. The monument is close to the shore of Lough Gowna near the village of Aghacliff in County Longford and is accessible to the public by a footpath.

The Malin More dolmen, County Donegal.

One of the strangest and most impressive of the remaining megalithic structures in County Donegal is the set of six dolmens at Malin More, not far from Glencolumbkille. This monument has six megalithic chambers set in an east to west line; the sites were once joined by a long cairn.

The east dolmen at Malin Mor, converted into a hen house. Photo by William A. Green.
The east dolmen at Malin Mor, converted into a hen house. Photo by William A. Green.

The two structures at the ends were truely massive. The capstone of the west dolmen has fallen off and stands upright. The capstone of the east dolmen is just as large.

The Giant's Griddle in Tawnatruffan, view looking west to Nephin Mountain in County Mayo.
Another Giant's Griddle with a massive capstone near Tawnatruffan in west County Sligo.
The Giant's Griddle in County Sligo.
The Giant's Griddle, a fine dolmen in the Easkey river valley to the west of County Sligo.

Dolmens in Kilkenny and Carlow

Several of the following photos are from a trip to Kilkenny and the surrounding area in 2012. I am delighted to have been able to visit both the largest and the tallest dolmens in Ireland as well as several surprises including a few collapsed monuments, and all were located close to streams and rivers, possibly marking ancient fording places.

More recent theorys suggest that these monuments may be some kind of organic fertiliser banks for sprouting seeds which would have been cultivated in the areas around the monuments.

Collapsed dolmen in Carlow

Partly collapsed dolmen with a fine rippled pattern on the top of the huge granite capstone. By the banks of the river Slaney in east Co Carlow.

The Haroldstown dolmen

The beautiful Haroldstown dolmen in Co Carlow, located, close to an ancient ford no doubt, on the banks of the river Slaney.

The Haroldstown dolmen

The Haroldstown dolmen in Co Carlow.

The large dolmen at Owning near Piltown in Co Kilkenny

This large dolmen at Owning near Piltown in Co Kilkenny, has fine views west to Sliabhnaman. This dolmen is close to the rising of the river.

Leac an Scail

Leac an Scail, Ireland's tallest dolmen at 5 meters or 15 feet from the ground to the tip of the capstone. At the headwaters of the stream in Co Kilkenny, the view below is from the other side.

Leac an Scail

The Harristown dolmen in Co Carlow.

Collapsed dolmen in County Kilkenny

A collapsed dolmen with a massive capstone in south Kilkenny.

The Brownshill dolmen in County Carlow
The Brownshill dolmen in County Carlow, said to weigh somewhere between 100 and 150 tons.

Dolmens in County Dublin

County Dublin has some of the largest and most interesting examples of portal dolmens in Ireland. They are not all as well known or accessible as they were a century ago, but thankfully we have some fine photographs and illustrations from various sources.

Aideen's Grave
Aideen's Grave on the Hill of Howth.

Aideen's Grave, a massive collapsed dolmen on the Hill of Howth, mythical Benn Eder in County Dublin. From here a line crosses the country passing through Tara and Loughcrew and several other sites until it meets the west coast at Queen Maeve's cairn in Co Sligo. Watercolour from Fergusson's Rude Stone Monuments.

Aideen's Grave
Aideen's Grave, Howth Head, County Dublin in an old postcard.
The Brownshill dolmen in County Carlow

The Brownshill dolmen in County Carlow is said to be the largest in Ireland.

The Proleek dolmen
The Proleek dolmen, also known as the Giant's Load.
The famous Pentrie Ifan dolmen in Wales.
The famous Pentrie Ifan dolmen in Wales.
The Legannany dolmen
The Legannany dolmen in Co Antrim, photo from about 1890.
The Shanganagh dolmen
The Shanganagh dolmen, Ballybrack, County Dublin.
The Kilternan dolmen
The Kilternan dolmen, also in County Dublin.
The dolmen of the Four Maols
The dolmen of the Four Maols, Ballina, Co. Mayo.
Kilclooney dolmen
Kilclooney dolmen in County Donegal, with its fantastically enormous capstone. The second smaller dolmen on the left is another chamber; in the neolithic they would have been joined by a cairn.