Overview
The Cuilcagh Lakelands is one of only a handful of geoparks in the world that straddle an international border. Its 1,781 km² (178,100 hectares, largely in public ownership) run from the uplands of Fermanagh in Northern Ireland down into the drumlin lakelands of Cavan in the Republic, taking in more than fifty named sites. The big draws are the subterranean Marble Arch Caves, the elevated Cuilcagh Boardwalk across open bog, the limestone pavement of Cavan Burren Park, and the source of the River Shannon at Shannon Pot.
If you want a rule of thumb: walk the Cuilcagh boardwalk for the view on a clear day, and keep the Marble Arch cave tour in your back pocket for when the weather turns – it’s underground, so the rain doesn’t matter.
History and geology
The area became the world’s first cross-border geopark in 2008 and was designated a UNESCO Global Geopark in 2015. It’s jointly run by Fermanagh and Omagh District Council and Cavan County Council – a cooperative model that protects a landscape shaped over 895 million years, from Precambrian and Carboniferous rock through to glacial drumlins and blanket bog.
Human history runs nearly as deep. There’s a notably high concentration of archaeology: prehistoric tombs (the Burren Forest in west Cavan has striking examples), Iron Age forts, early Christian monasteries, and Plantation castles. The best-preserved of the last is Monea Castle, while Clough Oughter Castle sits on its own island in Lough Oughter.
Walking and hiking
The trail network runs from short family loops to full-day routes, and most are free to access.
- Cuilcagh Boardwalk Trail – the headline walk, a timber boardwalk laid across blanket bog and climbing toward the summit ridge. It’s a steady half-day round trip with a viewing platform at the top, and there’s a free car park at the trailhead. Bring layers: the bog is exposed and the weather changes fast.
- Cavan Way – links Blacklion to Dowra via Shannon Pot, following quiet roads, forest tracks and open moorland, marked with yellow-on-black waymarks.
- Cavan Burren Park trails – several short marked routes through a rare limestone landscape of dolines, sinkholes, glacial erratics and the dramatic “Lost Valley”. Trail 1 is fully wheelchair accessible.
Caves, castles and waterways
Beyond the walking routes, the geopark has guided cave tours, lake activities and forest drives.
- Marble Arch Caves – guided tours descend into a river-carved system of stalactites and stalagmites. This is the one site that charges admission, and tours can sell out, so book ahead and check current tour times before you travel.
- Shannon Pot – the official source of Ireland’s longest river, in a quiet woodland setting. Access has been intermittent due to nearby works, so check local signage before heading out.
- Lough Navar Forest – 2,600 hectares of bog, heath and lake, with a scenic 10 km forest drive that opens onto one of the finest views in the country at the Cliffs of Magho.
- Killykeen Forest Park – lakeside woodland on Lough Oughter with summer bike and canoe hire; the nature trail is wheelchair accessible and good for birdwatching.
- Tully Castle and Big Dog Forest – Tully Castle, a seventeenth-century fortified house on Lower Lough Erne, has a short circular walk and a boat jetty. Big Dog Forest, further off, offers remote off-track walking through coniferous plantation.
Cyclists are well served too: the Scarplands Cycle Trail runs about 60 km from Belcoo to Lough Navar Forest, with shorter options such as the 21 km Aghanaglack Loop.
Getting there and planning your visit
The geopark spans both sides of the border, so plan the route accordingly. There’s no single visitor centre and no one entry point – the geopark office is at the MacNean Resource Centre, Main Street, Blacklion, Co. Cavan. Main car parks sit at Marble Arch Caves, the Cuilcagh Boardwalk trailhead, Cavan Burren Park and Killykeen Forest Park. The N87 (via Blacklion) and N3 (via Cavan) are the primary road links, with rail access at Enniskillen and onward bus connections. Bicycle hire is available from private operators on both sides of the border.
Because the park crosses the border, you’ll move between euro and sterling and between kilometres and miles on the signs – worth knowing before you set off. Pick two or three sites within a short drive of each other rather than trying to cover the whole thing: Marble Arch, the Cuilcagh boardwalk and Cavan Burren make a full, satisfying day on their own. In spring or autumn, bring waterproofs and sturdy footwear, as the bog trails and limestone paths turn slick after rain.