Banner: Knocknarea at Sunset.
The fine dolmen at Cloghcor at the end of the Magherow peninsula to the north of County Sligo. The view is to a hazy Benbulben in the east.

Cloghcor portal dolmen

In the townland of Cloghcor pronounced by the country people Cloghcur there is a megalith, situated close to the ruins of the Castle of Ardtarmon, near Raughley, and about 200 yards South of the road. It is marked on the Ordnance 6" Sheet as a Druid's Altar, and appears originally to have consisted of three lofty uprights, surmounted by a covering-slab; the two remaining pillars are upwards of nine feet in height above the present surface of the soil; the third had, at some remote period, succumbed either to violence or atmospheric action, and lies fractured beneath the covering-slab, which has fallen outwards and to the westward. The greatest length of this slab is 12 feet 6 inches from East to West, and it is upwards of 2 feet in thickness.

W. G. Wood-Martin, Rude Stone Monuments, 1888.

This fine portal dolmen is found on the summit of a drumlin near the end of the Magherow peninsula, to the west of north County Sligo. The name Clough Cor means "The Stone on the Round Hill". On the old Ordinance Survey maps the dolmen is marked as a druids altar, a common misconception from the antiquarian era.

There are about 200 portal dolmens in Ireland, the oldest currently dated being Poulnabrone in County Clare at 3,800 BC. Cloughcor is privately owned and permission from the landowner must be obtained to visit the monument, which is on a working farm.

Cloghcor dolmen from an illustration by William Wakeman in Rude Stone Monuments by W. G. Wood-Martin.
Cloghcor dolmen from an illustration by William Wakeman in Rude Stone Monuments by W. G. Wood-Martin.

The impressive example at Cloughcor is constructed in an unusual location 40 meters above sea level at the summit of the hill. Such monuments are generally found in sheltered areas, often in a river valley or close to a stream. Cloghcor commands fantastic views of the surrounding countryside, especially to the south, where Knocknarea and Queen Maeve's cairn stand out across Drumcliffe Bay.

Equinox Alignment

There is a fine view towards the Dartry range in the east where the heads of Benwisken, Benbulben and King's Mountain make a striking horizon. In an exciting recent discovery, landowner Leo Leydon noticed that the profile of the dolmen echoes the shape of King's Mountain ten kilometers to the east.

Cloghcor dolmen location and alignment.
Cloghcor dolmen location 400 meters from the sea and alignment towards the equinox sunrises.

At sunrise on the spring and autumn equinoxes, the sun emerges from a notch in the head of King's Mountain in a spectacular display of light and shadow. This is a spectacular visual alignment, especially as portal dolmens generally do not exhibit astronomical orientations. The dolmen casts a stricking shadow, showing how these monuments may have functioned as sundials.

Newly discovered megalithic art at Cloughcor, photograph © Ciaran McHugh.
Newly discovered megalithic art at Cloughcor, photograph © Ciarán McHugh.

The portal dolmen

The monument consists of two massive portal stones, each more than three meters high. The stones are of an ingeous rock, perhaps sandstone, and have many fine veins of quartz crystals running through them.

The colossal capstone of the Cloghcor dolmen.
The colossal capstone of the Cloghcor dolmen.

The massive sandstone capstone has slid backwards off the portals, and now lies behind them. When complete it would have been a truely imposing monument, highly visible from many miles around. Leo Leyden, the landowner is an enthusiastic archaeologist and has surveyed many monuments in the local landscape. A collection of quernstones he found have been donated to the National Museum.

Quern stones at Cloghcor.
The collection of quern stones found near Cloghcor dolmen. They are now in the National Museum.

Megalithic art

In September of 2020, while filming a clip for the Sligo Commumity Archaeology Project, Tamlyn McHugh, while interviewing Leo Leydon, noticed a set of cup marks on a stone in the chamber. This is an exciting discovery as portal dolmen art is extremely rare in Ireland. Subsequent night time images revealed a collection of fourteen examples of engraved cups.

Leo Leydon at the Cloughcor portal dolmen. Photograph © Maura Barrett.
Leo Leydon at the Cloughcor portal dolmen. Photograph © Maura Barrett.

The Cloghcor dolmen has not been excavated in modern times. There are two other megaliths in the area: the central court cairn in a field near Maugherow church, a few hundred meters to the north, and a largely ruined, unclassified monument near the shore not far to the east. The impressive promontory fort at Knocklane is also close by.

The impressive cliff-edge fort at Knocklane in County Sligo. Knocknarea is visible across the bay.