Overview
The point where three counties meet on Sliabh Beagh has a name: the Three County Hollow, a flat, windswept depression where Monaghan, Fermanagh and Tyrone all touch. It sums up the place – low, boggy, exposed, and far more remote-feeling than its closeness to main roads suggests. Sliabh Beagh (Irish: Sliabh Beatha) is a plateau of blanket bog, peat-clad hills and shallow upland loughs, topping out at 380m (1,250ft). The true summit sits on the Fermanagh–Tyrone border; the highest ground in County Monaghan is a point just east of it.
Blanket bog and small lakes spread across the exposed ground, a mosaic of sphagnum moss, dwarf heath and shallow streams that feeds the Finn River. The Slieve Beagh Special Protection Area protects habitat for the hen harrier, so this is a place to tread lightly.
History and mythology
The name Sliabh Beatha is usually read as ‘mountain of birch’, but folklore gives it another root: Bith, a mythic figure said to be a son of Noah, reputedly buried in a summit cairn known as the Cairn of Doocarn.
The plateau carries the weight of the penal era too. Leacht a’tSagairt (the Priest’s Stone) is a Mass rock topped by a large Celtic cross. Tradition holds that a priest-hunter shot the priest – named as Fr McKenna – while he was saying Mass here on Christmas Day around 1754. The nearby Bragan Penal Cross marks the same killing. The priest-hunter was later run down and killed near Emyvale by the rapparee leader Shane Bernagh (also recorded as Shane Barnagh), who used this rough country to stay ahead of the law.
St Patrick’s Chair and Well sits above Altadaven Wood – a boulder-hewn seat and holy well thought to predate Christianity and later folded into Patrician tradition. In 2000 the People’s Millennium Forests scheme planted native saplings in the Favour Royal Forest, one tree for every household in the country, restoring a fragment of the woodland that once covered these slopes.
Walking the trails
Monaghan Tourism lists the Tra, Rock, Bragan and Esh loops, which are the published walks around Knockatallon. The Bragan Walk uses minor country roads, giving views across the bog from firm ground.
Use the published map and parking guidance, take care around traffic and leave farm entrances clear. Carry a map or a downloaded GPS track, because the terrain turns disorienting in mist. Carry layers for wind and rain and stay out of the bog away from marked routes.
Key sites and landmarks
These landmarks are named for the history above. Many lie on open upland or private land away from the published loops, so do not treat them as destinations unless a published route or official guidance takes you there.
- St Patrick’s Chair and Well – The ancient seat and holy well above Altadaven Wood, still a spot for quiet reflection.
- Bragan Penal Cross – A remote, atmospheric memorial to the priest killed during the penal era.
- Muckle Rocks and Shane Barnagh’s Lough – An outcrop tied to the outlaw legends, near the Coolbrooke River.
- Mullaghfad Forest and lakes – Lough Cushkeery and Jenkin Lough draw birdwatchers and red-squirrel spotters.
- Tully Forest – A known stronghold for native red squirrels; early morning gives the best chance of seeing them.
- Mullaghfad Church – A remote 19th-century stone church ringed by old yews.
Wildlife and nature
The bog and lake system supports more life than the bare moor suggests. Hen harriers quarter the heath, and golden plover and red grouse nest on the open ground. The replanted native woodlands have drawn back red squirrels, occasionally seen along the forest tracks. Nesting activity peaks from late spring to early autumn, when the heather also comes into bloom. Early-morning mist over the loughs makes for good photography without any special kit.
Practical information
- Getting there – Sliabh Beagh is a car-only destination. Use the parking guidance published with the walk you choose.
- Navigation – Carry a physical map or offline GPS; mobile coverage can be patchy across the moor.
- Seasonality – The bog becomes waterlogged and treacherous in winter. Late spring to early autumn gives the firmest ground and longest daylight.
- Safety and conservation – Weather changes fast up here. Waterproof boots, layers and a compass are essential. Stay on marked routes, keep off the sphagnum and take all litter home.
Check both the Met Éireann and Met Office forecasts before you set out – visibility can drop to near zero in the hollows. There are no cafés on the trail, so bring water and food.