Overview
Poisoned Glen (Irish: An Gleann Neamhe) lies in the heart of the Derryveagh Mountains, just outside the Gaeltacht village of Dunlewey in County Donegal. The valley stretches beneath the iconic profile of Mount Errigal, the highest peak in the range, and opens onto the shimmering waters of Dunlewey Lough. A 19th‑century white‑marble church crowns the glen’s entrance, framing the dramatic rock faces that dominate the horizon. Within this setting sits Bearnas Buttress – a 240 m high granite wall that is Ireland’s largest continuous rock face, attracting climbers from across the island.
Legends and Naming
Local folklore says the valley earned its ominous name when the one‑eyed giant Balor of Tory was slain here; the poison from his eye was said to have seeped into the rock, “poisoning” the glen. A more mundane explanation points to a cartographic mistake: the Irish word neamh (heaven) was misread as neimhe (poison) by an English map‑maker, and the misnomer endured.
Walking the Poisoned Glen Trail
- Route: A 4 km (2.5 mi) circular, unpaved trail starts from a lay‑by on the R251. The path follows the right bank of the Owenabhainn River, passes the ruined 1830 marble church and several small waterfalls before returning via a gentle ascent to the viewpoint.
- Difficulty: Easy to moderate – the track is well‑marked but can become muddy after rain; sturdy waterproof boots are recommended.
- Highlights: The marble church, hidden cascades, and the panoramic view of Mount Errigal from the designated Poison Glen View Point. Photographers love the contrast of dark crags against the green valley.
- Amenities: Free parking at the lay‑by, a summer‑season coffee van, benches and a buggy‑friendly surface make the route family‑friendly.
Climbing Bearnas Buttress
- Wall profile: North‑facing granite, 150‑240 m high, offering routes from Diff to E4.
- Typical routes: Classic lines such as “The Poisoned” (E2 5a) and “Bearnas Direct” (E3 6a) provide a mix of slab, crack and occasional overhang.
- Seasonality: The wall stays damp for much of the year; the best climbing windows are late spring and early autumn when dry periods are more common.
- Safety: Check the weather forecast, bring a rope, quickdraws and be prepared for limited dry spells. The descent is via a fixed rope‑line at the top of the crag.
Nearby Attractions
- Assaranca Waterfall (/assaranca-waterfall/) – a short 10 km drive north‑west, this 70‑metre cascade offers a scenic walk and picnic area.
- Binion Caravan Site and Hill Walk (/binion/) – a pleasant hill walk with views over the Derryveagh range, ideal for a post‑glenn hike.
- Dunlewey Lough – a tranquil spot for a lakeside stroll or a paddle in calm weather.