№ 25Underground · County Fermanagh, Northern Ireland
Marble Arch Caves
A river runs through it: caverns of streaked limestone crossed by boat, under the Fermanagh hills.
Photographs Gerd Eichmann (CC BY-SA 4.0) · Rossographer (CC BY-SA 2.0) · Wikimedia Commons
Under the slopes of Cuilcagh, three rivers sink into the limestone and become one underground: the Cladagh, flowing through a cave system of streaked calcite walls, mirror pools and chambers hung with straw stalactites finer than drinking straws.
Tours begin, water levels permitting, with a boat glide across an underground lake — the guides' commentary echoing off a ceiling forty-five thousand years in the making. Above ground, the Marble Arch itself frames the river's re-emergence into a nature reserve of mossy gorge.
The knowledge
- Getting there
- Marlbank, near Florencecourt, County Fermanagh; guided tours roughly March to October — heavy rain closes the lower passages, so check ahead.
- Best time
- After a dry week, when the boat section is running and the pools are glass.
- Local tip
- Add the Cuilcagh boardwalk nearby if your legs want a skyline to go with the underworld.
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