Derryveagh Mountains – Errigal & Glenveagh

Overview

The Derryveagh Mountains hold the most thinly populated ground in Ireland: a wide quartzite interior of bog, lake and bare rock that separates the coastal Gaeltacht around Gweedore from the inland towns of Ballybofey and Letterkenny. At their centre sits Glenveagh National Park, a free wilderness of woodlands, peatlands and the long dark slot of Lough Veagh. The high point, and the thing most people come for, is Errigal – Donegal’s highest peak at 751 m and the steepest and most southerly of the chain that locals call the Seven Sisters.

If you only have time for one thing and you are reasonably fit, climb Errigal. If you are not here to climb, walk in to Glenveagh Castle along the lake instead – it is the better use of a flat afternoon.

Climbing Errigal

Errigal was voted Ireland’s most iconic mountain by Walking & Hiking Ireland in 2009, and on a clear day it earns it: a pink quartzite cone that catches the light from miles off. The usual route starts from the car park on the R251 near Dunlewey and follows a gravel path to the base before a steep, scree-strewn pull to the top, with stone steps helping on the worst of it. Allow a couple of hours of effort. The sting in the tail is the narrow pass linking Errigal’s twin summits – fine in still, clear weather, genuinely exposed in wind or cloud. The reward is a view down over Dunlewey Lough and across the Poisoned Glen.

One honest warning: this is a proper mountain, not a stroll. The quartzite is loose and slippery when wet, the cloud comes down fast, and there is no shelter on top. Carry a map, a windproof layer and the sense to turn back. The park’s own advice is the right one – avoid the summits in bad weather.

The other peaks

• Muckish – the “pig’s back”, a flat-topped 666 m plateau with an almost lunar summit. The out-and-back from a lay-by on the R256 follows a narrow ridge with sweeping coastal views.
• Slieve Snaght – a more forgiving climb to a broad summit plateau, from which Errigal, Muckish and the north-west coast line up in a single sweep.

Glenveagh: the lake, the castle and the walk in

The valley floor is the easy half of the Derryveaghs. From the visitor centre it is a 4 km walk along the shore of Lough Veagh to Glenveagh Castle, a castellated Victorian house built for Captain John George Adair in the 1860s and 70s on the edge of the water. A shuttle bus covers the same route if the legs aren’t willing – there is a charge, and the park raised its visitor-service prices in 2026, so check the current rate rather than trusting an old figure. The gardens around the castle are the surprise: rhododendrons, Eucryphia and other tender species that only survive this far north because the Atlantic keeps the frost off.

Adair is also why the place carries a darker story. In 1861 he evicted 244 of his tenants from the surrounding townlands in what became known as the Derryveagh Evictions, clearing the glen for sheep and, later, deer. The visitor centre runs free daily exhibitions on the evictions, on the golden eagle reintroduction and on the national parks, with short films worth twenty minutes before you set off. A lighter footnote: Greta Garbo stayed at the castle and asked for the pink candy-striped room.

For families or anyone short on time, the gentle 1 km circuit by the lakeshore gives you the castle view without the full walk in.

Wildlife

The park’s mix of bog, oak wood and open water carries red deer, mountain hares and otters, and the higher ground is hunting country for golden eagles and peregrine falcons – the eagles thanks to a long-running reintroduction project run from the park. The wider Derryveagh and Glendowan Mountains are a designated Special Protection Area for upland birds. Bring binoculars, and keep dogs on a lead through the ground-nesting season from March to July.

Cycling and getting around the park

Bike hire is available from the main visitor car park, roughly 10am to 5pm, but only from mid-June through September – outside those months bring your own or plan to walk. The estate’s gravel tracks make for easy, mostly level riding along the glen; the mountain ridges themselves are for walkers, not bikes.

Scenic drives

The R251 around the north side of Errigal is the drive to make, with pull-ins that frame the cone against the sky – best an hour before sunset, when the quartzite turns properly pink. Genuinely close stops, rather than the far-flung kind, include Glebe House and Gallery and the Colmcille Heritage Centre over at Church Hill by Lough Gartan, both a short drive from the park.

Practical information

Entry to the mountains and to Glenveagh National Park is free. The park is open daily, weather permitting.

Getting there – By car, follow the N56 then the R251 towards Gweedore; the main car park is signposted. Without a car, Local Link bus 271 (Burtonport – Letterkenny) stops daily at the flagpole in the park car park. Heritage Card holders get free castle tours and shuttle tickets.

Accessibility – Electric buses provide wheelchair access within the park, but the mountain trails are steep and uneven and not suitable for wheelchairs. Accessible toilets are at the Visitor Centre and Castle.

Fire risk – In dry spells the park issues fire warnings and closes off open flame; don’t light fires anywhere on the hills, and check the website’s alerts before you travel in summer.

The single best move is to arrive before midday, walk the lakeshore to gauge the cloud on Errigal, and only commit to the summit if the top is clear.