The Ring of Gullion

  • Written by  Natalie Hoare
  • Published in AONB
The view from one of the hills surrounding Slieve Gullion down to Cam Lough, a glacial ribbon lake and area of special scientific interest. Image: The view from one of the hills surrounding Slieve Gullion down to Cam Lough, a glacial ribbon lake and area of special scientific interest. Image: Gary McParland
The evocatively named Ring of Gullion Area of Outstanding Natural Beauty, which encircles an impressive ring dyke, the formation of which has both puzzled geologists and inspired a rich folklore

If you’d come here three or four years ago, you would have seen Army observation towers all through here,’ says Ron Murray, guide and former area of outstanding natural beauty (AONB) officer. ‘And there would have been helicopters flying in and out all the time – the Army base at Bessbrook, on the edge of the Ring of Gullion, was the busiest helicopter port in Europe at one time.’

I bring the car to a stop on a track on the southern slopes of Slieve (meaning ‘mountain’) Gullion and peer through a rain-splattered windscreen, trying to picture such a scene. A slightly blurred view of verdant fields, neatly divided by hedgerows and uneven stone walls, gently falls away towards the small village of Forkhill and, beyond it, Crossmaglen. In a nearby field, a mournful-looking cow stares back at me, chewing thoughtfully, its flanks glossy from the rain.

The British Army had a significant presence in this part of Northern Ireland during the ‘Troubles’ and, as a predominantly Republican IRA stronghold, South Armagh was a flashpoint for many years. At the height of the Troubles, troops and supplies were brought in by helicopter, as they were seen to be too vulnerable to mines on the roads. Today, a decade after the ceasefire, it’s a very different scene.

The-Ring-of-Gullion3The patchwork of fi elds below Slieve Gullion. Image: Chris Hill/Scenic Ireland



Close to the border with the Republic of Ireland and southwest of the Mourne Mountains, the Ring of Gullion AONB takes its name from the ring of low hills that encircles Slieve Gullion.

Lying at the centre of the AONB, Slieve Gullion is the highest point in County Armagh, a rounded, 573-metre-tall dome that’s blanketed in rich wildlife habitats of heath, bog and woodland. On a clear day, it’s possible to see as far as Lough Neagh, west of Belfast, and the Wicklow Mountains, south of Dublin, from the summit. But, sadly, today isn’t a clear day.

Far from it, and our summit bid was abandoned earlier due to the increasingly wet weather and diminishing visibility.

The mountain was formed on the weathered remains of an extinct volcano, while its surrounding ring, which measures up to 15 kilometres in diameter, is considered to be the best-preserved ring dyke in the British Isles and has shed light on a number of geological processes.

‘Fifty eight million years ago, there was a massive volcano here,’ explains Murray. ‘But at that time, it slipped, and as it collapsed, a more or less circular fault line was formed around the edge of the volcano, which pushed igneous volcanic material out to the edges, forming the ring dyke.’

Curiously, Slieve Gullion itself is more recent than the ring dyke, and its origins have both fascinated and confused geologists. ‘If you go back to about 58 million years ago, at the centre of the caldera, you have renewed volcanic activity underground. Slieve Gullion consists of 13 layers of alternating types of rock – basaltic and granitic – which are not normally rocks that you would find occurring together,’ says Murray. ‘This sort of rock intermingling on this mountain was one of the things that really puzzled people.’

Slieve Gullion and the ring dyke have long drawn geologists from all over the world and have featured in numerous scientific papers and geological debates. ‘This was the first ring dyke in the world that was ever studied and the first to be mapped,’ says Murray. ‘And a lot of the theories of volcanicity, rock intermingling and igneous activity were formed using Slieve Gullion as a model. The debate about precisely how the ring dyke formed is still ongoing.’

The dramatic volcanic landscape produced by such powerful subterranean forces has since been softened by a succession of ice ages that started 25,000 years ago, lasting until around 10,000 years ago. In that time, mighty rivers of ice sheared off the region’s sharp edges and carved deep valleys through weaknesses in the rocks in the ring.

The-Ring-of-Gullion1Set on a level terrace on the western slopes of Slieve Gullion, Ballykeel Dolmen has been dated to between 4000 and 2500 BC. Image: Chris Hill/Scenic Ireland



The complexities of the region’s geology and resultant landscape have, in turn, had a big influence on its equally complex and no less fascinating history and cultural heritage.

People have lived in the Ring of Gullion for more than 6,000 years, and in that time, the land has inspired a wealth of stories, music and poetry. Slieve Gullion features often in Irish mythology, with a number of legends set on its slopes – and even today, many of the locals I encounter are happy to reel off a story or two, one of which warned me not to swim in the lake on the summit plateau of Slieve Gullion. To this day, the superstition survives that if you bathe in the waters of the Lough of Calleach Béara, your hair will turn white, as did that of the mythical hunter-warrior Finn McCool. The Celtic warrior, who is also credited with building Antrim’s Giant’s Causeway, was bewitched by a woman on the summit of Slieve Gullion and, venturing into the lake to fetch a ring she had dropped, emerged old and weak.

The area also had strategic importance. During the Iron Age, it was a frontier between the tribes of Ulster and other provinces, and an extensive earthwork fortification known as the Dorsey Ramparts was constructed. One of the few confirmed Iron Age monuments in Northern Ireland, it sat astride an important historic route into the area.

A natural defensive feature in the area near Jonesborough, known as the ‘Gap of the North’ and later the ‘Gateway to Ulster’, played an important role in local history. It was a strategic route into the ancient kingdom of Ulaidh (which later became Ulster – one of Ireland’s four modern-day provinces) and stayed under Irish control until the early 17th century. Lord Deputy Mountjoy then built Moyry Castle (which is still visible today) after seizing control of the pass.

‘At that time, Ulster was the only Irish province that wasn’t under English rule,’ explains Una Walsh, a local guide and passionate historian with deep roots in South Armagh.‘This area was the end of what was known as the Pale – the area the English controlled from Dublin Castle. The Irish chieftains ruling the province of Ulster managed to defeat the English at several battles, but were eventually themselves defeated and forced to withdraw through this pass in South Armagh.’

Glimpses into these and other periods of the region’s history can be achieved by visiting some of the abundant historical monuments found in and around the AONB. For example, the remains of 20 or so large stone tombs can be found in prominent positions overlooking the surrounding countryside. Michael McShane, a local historian who works at the Cardinal Ó Fiaich Heritage Centre in Cullyhanna, explains that there are three Neolithic burial monuments within the Slieve Gullion area: Ballykeel Dolmen at the bottom of the mountain, the Slieve Gullion South Cairn and Passage Grave on the south summit, and the Slieve Gullion North Cairn on the northern side. ‘The South Cairn is regarded as the highest surviving passage tomb in the British Isles,’ says McShane. ‘It’s amazing that you have that concentration of monuments in such a small area.’

The-Ring-of-Gullion2Cam Lough at sunset. The area around the lough contains excellent examples of a range of deglacial landforms, including eskers, flat-topped deltas and kettle holes. Image: Gary McParland



A big telecommunications mast at Forkhill is one of the few remaining visible clues to the area’s most recent conflict. But things have moved on a lot since then. ‘All of the [military] installations have gone,’ says Murray. ‘There are only police stations in Crossmaglen, Bessbrook and Newry now. But as you can see, historically, it’s not just the past 20 or 30 years [that have seen unrest]. It goes back a long, long way.’

And, when you’ve had enough of gazing at the incredible ring dyke, a lot of that rich and vibrant history and cultural heritage remains surprisingly accessible here in the Ring of Gullion. ‘All of the monuments are testimony to the fact that people here have always had a high regard for their heritage,’ says Walsh. ‘Yes, they’re protected now by the Northern Ireland Environment Agency, but local people protected them long before then. And we want to tell more people about that history – not just of the past few decades, but well beyond that. There’s far more to this area than the Troubles.’



Show me the ring

‘You get some fantastic views from the top of Slieve Gullion – only from there can you appreciate the complete ring dyke. You can also see Slemish, an extinct volcano in County Antrim, where St Patrick was originally a shepherd; you can see Lough Neagh, the UK’s largest lake, and Slieve Gallion, which is halfway to the north coast, and much more.’

Ron Murray, guide and former AONB officer

Which townland am I in?

‘My father and I were responsible for putting in the townland boundary stones in this area. Townlands are a marking system of land that’s unique to Ireland. The system existed up until 1972 [when Royal Mail introduced the postcode and road-name system]. There are a total of 62,205 townlands across Ireland – the smallest officially defined area of land. We started a project to reintroduce the stones because people were starting to forget, and it’s important that we remember where they were.’

Una Walsh, local archaeology and heritage guide, Cardinal Ó Fiaich Heritage Centre

Set eyes on a sea lough

‘Another great viewpoint is Flagstaff viewpoint, near Jonesborough. You have a fantastic view right down Carlingford Lough and the east coast of Ireland.’

Ron Murray, guide and former AONB officer

Read ancient script

‘I love going to the Kilnasaggart Stone. The inscription on it dates back to about 700 AD, and it’s known as the earliest Irish literature that has been written down. It’s in a very secluded place, and the tranquillity of it is beyond belief. It stands in a graveyard, but you wouldn’t believe it was a graveyard unless you knew part of the history.’

Michael McShane, Cardinal Ó Fiaich Heritage Centre

For more information about the Ring of Gullion and the other AONBs in Northern Ireland, call 0800 039 7000 or visit


First published October 2009

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