Overview
The Seven Sisters is a chain of seven peaks in the Derryveagh Mountains of north-west County Donegal, and it forms one of the most recognisable skylines in Ulster. Running south-west to north-east, the seven are: Errigal (751 m), Mackoght, or Wee Errigal (555 m), Aghla More (581 m), Ardloughnabrackbaddy (473 m), Aghla Beg (603 m), Crocknalaragagh (471 m) and Muckish (666 m). The line swings from the flat, table-topped bulk of Muckish at one end to the sharp quartzite cone of Errigal at the other, crossing open bog, heather and loose scree in between.
You can climb any one of them on its own – Errigal and Muckish are popular half-day summits in their own right – but the full ridge is the prize, and it’s a serious undertaking rather than a casual walk.
The traverse
The classic traverse runs about 21 km and takes most walkers the best part of a day: the hiking-route figures give around 1,671 m of ascent and 1,787 m of descent, while AllTrails logs the same line at 21.7 km and 1,769 m of climbing. Either way, it’s long and relentless. Most people start at the Miners Path car park near Muckish and finish at the Errigal car park, working south-westwards.
The trail is unsignposted throughout and follows a patchwork of old sheep paths, faint ridgelines and exposed scree. The pulls onto Aghla Beg and the final climb of Errigal are the steepest and can be punishing late in the day. After the drop from Aghla More the route dips into the sheltered valley of Altan Lake, where the stone ruins of Altan Farm sit on the shoreline – a natural rest stop, and a popular wild-camping spot for walkers splitting the traverse over two days.
The views are the payoff: north to the Atlantic, and a near-continuous ridgeline that lets you see where you’ve come from and where you’re going for most of the day. Cairns and trig points mark several of the tops.
History and setting
This is Gaeltacht country, where Irish is still the everyday language, and the place names read like a description of the ground. Muckish is An Mhucais, “the pig’s back”, for the broad table-top that does look like a pig at rest from the north-west. Errigal, An Earagail, is Donegal’s highest peak and a landmark visible far out to sea. Errigal and its slopes sit within a Special Area of Conservation, protecting a complex geology and rare mountain habitats.
The range also gives its name to the Seven Sisters Skyline, a 55 km ultra-mountain race with around 4,000 m of ascent held each September out of Dunlewey village – a reminder of just how much vertical ground is packed into this stretch of Donegal.
Practical information and safety
This is a serious mountain day that needs proper preparation. Because the route isn’t signposted, navigation is on you: carry a detailed OS map, a compass, and a charged phone or GPS. The ground turns boggy and wet after rain, so sturdy boots with good ankle support are non-negotiable.
Weather in the Derryveaghs shifts fast, and low cloud can cut visibility to near zero on the tops while the wind rises on exposed ridges. Pack waterproofs, a warm layer, a head torch and enough food and water for a full day. Mobile signal is patchy across much of the traverse, so tell someone your route and expected return time. In an emergency dial 999 or 112 for the gardaí, who work with Donegal Mountain Rescue.
The best conditions are usually late spring through early autumn. Summer afternoons can throw up sudden storms, so start early, leave ample daylight for the finish, close gates behind you and follow Leave No Trace.
Getting there
The Seven Sisters are best reached by car. The Miners Path start at Muckish and the Errigal finish are both off the mountain roads through the Derryveaghs, and there’s parking at Dunlewey near the Errigal end – handy if you can arrange a shuttle or a second car back to the start, since this is a point-to-point route rather than a loop. Public transport to the trailheads is very limited. The nearest airports are Donegal (about 30 minutes) and Derry (about an hour), and Letterkenny is the main town for fuel, groceries and accommodation.
If you’re building a longer trip, the nearby Bluestack Mountains offer more walking over a softer landscape of rounded hills and deep glens.